River Encounters

Neighbors

Wildlife

CR 1/4

Monstrous Diving Spider, Tiny

Size/Type:Tiny Vermin
Hit Dice:½ d8 (2 hp)
Initiative:+3
Speed:20 ft. (4 squares), climb 10 ft., swim 30 ft.
Armor Class:15 (+2 size, +3 Dex), touch 15, flat-footed 12
Base Attack/Grapple:+0/-12
Attack:Bite +5 melee (1d3-4 plus poison)
Full Attack:Bite +5 melee (1d3-4 plus poison)
Space/Reach:2½ ft./0 ft.
Special Attacks:Poison
Special Qualities:Darkvision 60 ft., tremorsense 60 ft., vermin traits
Saves:Fort +2, Ref +3, Will +0
Abilities:Str 3, Dex 17, Con 10, Int Ø, Wis 10, Cha 2
Skills: Climb +11, Hide +15, Jump -4, Spot +4
Feats: Weapon Finesse (b)
Environment: Temperate forests
Organization: Colony (8-16)
Challenge Rating: ¼
Treasure: None
Advancement: —
Level Adjustment: —

Poison (Ex): A tiny diving spider has a poisonous bite. Fort DC 10, primary and secondary damage 1d2 str.

Tremorsense (Ex): A diving spider can detect and pinpoint any creature or object within 60 feet in contact with the ground or in the water.

Hold Breath (Ex): A diving spider can hold its breath for a number of rounds equal to 4 × its Constitution score before it risks drowning. For a typical tiny diving spider this is 40 rounds, or 4 minutes.

Skills: Diving spiders have a +4 racial bonus on Hide and Spot checks and a +8 racial bonus on Climb checks. A monstrous spider can always choose to take 10 on Climb checks, even if rushed or threatened. Monstrous spiders use either their Strength or Dexterity modifier for Climb checks, whichever is higher. A tiny diving spider takes a -4 on Swim checks due to its low strength. It has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

Monstrous Scorpion, Tiny

CR 1/3

Giant Fire Beetle*

Giant Leech

Small Vermin (Aquatic)
Hit Dice: 1d8 (4 hp)
Initiative: +1
Speed: Swim 10 ft. (2 squares)
Armor Class: 12 (+1 size, +1 Dex), touch 12, flat-footed 11
BaseAttack/Grapple: +0/–6
Attack: Bite +2 melee (1 plus blood drain)
Full Attack: Bite +2 melee (1 plus blood drain)
Space/Reach: 5 ft./5 ft.
Special Attacks: Anesthetize, attach, blood drain, disease
Special Qualities: Blindsight 10 ft., scent
Saves: Fort +2, Ref +1, Will –1
Abilities: Str 6, Dex 12, Con 11, Int —, Wis 8, Cha 2
Skills: Hide +9, Swim +6
Feats: Weapon FinesseB
Environment: Warm marsh
Organization: Colony (2–5) or swarm (6–11)
Challenge Rating: 1/3
Treasure: None
Alignment: Always neutral
Advancement: 2–3 HD (Small)
Level Adjustment: —

This wormlike creature is the size of a human forearm. Its mouth is a round, suckerlike orifice.Giant leeches have little ability to attack foes in open water or clear terrain but can pose a serious danger to characters wading or swimming in murky or muddy water.

COMBAT

Giant leeches are found in murky water, where they can approach prey unseen. Characters might be attacked without even noticing. (DM Tip: Take note of the PCs’ Spot checks and AC before running an encounter with giant leeches. Record damage dealt by an undetected leech, but do not inform the player of the damage until his or her character notices the attack.)

Anesthetize (Ex): A creature bitten by a giant leech must succeed on a Spot check (opposed by the giant leech’s Hide check) to notice the attack if both the leech and its target are in murky water at least 2 feet deep. Each round of blood drain entitles the creature to another Spot check to notice the leech, with a cumulative +2 bonus on the check per round after the first. Characters attacked in clear water, or who have some means of detecting the leech without seeing it, notice the attack automatically.

Attach (Ex): If a giant leech hits with its bite attack, it uses its suckerlike mouth to latch onto the opponent’s body. It deals no additional damage when it is attached, but it drains blood (see below). An attached leech loses its Dexterity bonus to AC and has an AC of 11. An attached leech can be struck with a weapon or grappled itself. To remove an attached leech through grappling, the opponent must achieve a pin against the creature.

Blood Drain (Ex): A leech that is attached to its opponent deals 1 point of Constitution damage per round until it deals a total of 6 points, at which point it detaches from its target and swims off to digest its meal.

Disease (Ex): A creature bitten by a giant leech must succeed on a DC 15 Fortitude save or contract red ache (see page 292 of the Dungeon Master’s Guide).

Skills: Giant leeches have a +4 racial bonus on Hide checks. A giant leech has a +8 racial bonus on any Swim check to perform a special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

Jackal

CR 1/2

Monstrous Diving Spider, Small

Size/Type:Small Vermin
Hit Dice:1d8 (4 hp)
Initiative:+3
Speed:30 ft. (6 squares), climb 20 ft., swim 30 ft.
Armor Class:14 (+1 size, +3 Dex), touch 14, flat-footed 11
Base Attack/Grapple:+0/-6
Attack:Bite +4 melee (1d4-2 plus poison)
Full Attack:Bite +4 melee (1d4-2 plus poison)
Space/Reach:5 ft./5 ft.
Special Attacks:Poison
Special Qualities:Darkvision 60 ft., tremorsense 60 ft., vermin traits
Saves:Fort +2, Ref +3, Will +0
Abilities:Str 7, Dex 17, Con 10, Int Ø, Wis 10, Cha 2
Skills:Climb +11, Hide +11, Jump -2, Spot +4
Feats:Weapon Finesse (b)
Environment:Temperate forests
Organization:Colony (2-5) or swarm (6-11)
Challenge Rating:½
Treasure:None
Advancement:—
Level Adjustment:—

Poison (Ex): A small diving spider has a poisonous bite. Fort DC 10, primary and secondary damage 1d3 str.

Tremorsense (Ex): A diving spider can detect and pinpoint any creature or object within 60 feet in contact with the ground or in the water.

Hold Breath (Ex): A diving spider can hold its breath for a number of rounds equal to 4 × its Constitution score before it risks drowning. For a typical small diving spider this is 40 rounds, or 4 minutes.

Skills: Diving spiders have a +4 racial bonus on Hide and Spot checks and a +8 racial bonus on Climb checks. A monstrous spider can always choose to take 10 on Climb checks, even if rushed or threatened. Monstrous spiders use either their Strength or Dexterity modifier for Climb checks, whichever is higher. A small diving spider takes a -2 on Swim checks due to its low strength. It has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

Monstrous Scorpion, Small

CR 1

Hyena

Leech Swarm

Fine Vermin (Aquatic, Swarm)

Hit Dice: 2d8–2 (7 hp)
Initiative: +0
Speed: Swim 10 ft. (2 squares)
Armor Class: 18 (+8 size, +0 Dex, +0 natural), touch 18, flat-footed 18
BaseAttack/Grapple: +1/—
Attack: Swarm (1d6 plus blood drain)
Full Attack: Swarm (1d6 plus blood drain)
Space/Reach: 10 ft./0 ft.
Special Attacks: Anesthetize, blood drain, disease, distraction
Special Qualities: Immune to weapon damage, low-light vision, swarm traits
Saves: Fort +2, Ref +0, Will +1
Abilities: Str 1, Dex 11, Con 8, Int —, Wis 12, Cha 2
Skills: Hide +16, Swim +3
Feats: —
Environment: Warm marsh
Organization: Solitary or plague (2–4 swarms)
Challenge Rating: 1
Treasure: None
Alignment: Always neutral
Advancement: None
Level Adjustment: —

The water squirms with uncounted thumb-sized sluglike crea-tures, each one wriggling in an unsettling manner.Leeches are found in murky water, where they can approach prey unseen.

Combat

A leech swarm relies on stealth and blood drain to quietly disable its target. An unobservant creature can be drained dry without even realizing the cause of its weakness. (DM Tip: Take note of the PCs’ Spot checks and AC before running an encounter with a leech swarm. Record damage dealt by undetected leeches, but do not inform the player of the damage until his or her character notices the attack.)

Anesthetize (Ex): A creature attacked by a leech swarm must succeed on a Spot check (opposed by the swarm’s Hide check) to notice the attack if both the leech swarm and its target are in murky water at least 2 feet deep. Each round of blood drain entitles the creature to another Spot check to notice the leeches, with a cumulative +2 bonus on the check per round after the first. Characters attacked in clear water, or who have some means of detecting the leech swarm without seeing it, notice the attack automatically.

Blood Drain (Ex): Any living creature damaged by a leech swarm also takes 1 point of Constitution damage as the swarm drains its blood. This damage repeats every round thereafter unless the creature successfully exits the swarm and spends a full-round action removing leeches from its body.

Disease (Ex): A creature damaged by a leech swarm must succeed on a DC 15 Fortitude save or contract red ache (see page 292 of the Dungeon Master’s Guide).Distraction (Ex): Any living creature vulnerable to the leech swarm’s damage who notices the swarm and begins its turn with a swarm in its square is nauseated for 1 round; a DC 10 Fortitude save negates the effect. Even with a successful save, spellcasting or concentrating on spells within the area of a swarm requires a Concentration check (DC 20 + spell level). Using skills requiring patience and concentration requires a DC 20 Concentration check. The save DC is Constitution-based.

Swarm Traits (Ex): See page 316 of the Monster Manual.

Skills: A leech swarm has a +8 racial bonus on any Swim check to perform a special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

Monstrous Scorpion, Medium

CR 2

Cheetah*

Crocodile

CR 3

Brine Swimmer

Large Vermin
Hit Dice: 5d8+10 (32 hp)
Initiative: +3
Speed: 20 ft. (4 squares), swim 40 ft.
Armor Class: 17 (–1 size, +3 Dex, +5 natural), touch 12, flat-footed 14
Base Attack/Grapple: +3/+10
Attack: Bite +5 melee (1d6+4)
Full Attack: Bite +5 melee (1d6+4)
Space/Reach: 10 ft./5 ft.
Special Attacks: Improved grab, rake 1d4+1
Special Qualities: Immunity to acid and dehydration, low-light vision, snap turn, vermin traits
Saves: Fort +6, Ref +4, Will +1
Abilities: Str 17, Dex 16, Con 15, Int —, Wis 10, Cha 4
Skills: Swim +3
Feats: —
Environment: Warm aquatic
Organization: Solitary or colony (6–30)
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 6–10 HD (Large); 11–15 HD (Huge)
Level Adjustment: —

This large crustacean has dozens of feathery, flat legs and crushing mandibles. It flips through the salt water with great agility.Brine swimmers are a giant form of brine shrimp, perfectly adapted to the salty, shallow lakes of the waste. While ordinary brine shrimp feed on algae, these giant creatures eat fish, larval brine swimmers, and even young crocodiles if they can get them. They are a danger to any creature of Medium or smaller size that enters their territory. A brine swimmer’s many legs act as fins, gills, and food-gathering tools. They are fringed with bristles that both filter food from the water and tear at prey held in the creature’s mandibles. Brine sw immers swim constantly and seem to cavort as they twist and spin in the water. Brine swimmer eggs are able to withstand extended periods of drought. If a salt lake dries up, the eggs can survive for several years in a crystalline form, hatching within hours once they are immersed again. Brine swimmers and their eggs are an important food source for many waste-dwellers, although hunting the creatures is by no means safe.

Combat

A brine swimmer grabs at prey with its mandibles, then holds on and rakes with its legs. Brine swimmers can make sudden turns by fl exing their segmented abdomens, and they use this surprising maneuverability both when hunting and when attempting to escape danger. Brine swimmers generally travel in large groups, and a movement by one toward a food source soon brings dozens of others.

Improved Grab (Ex): To use this ability, a brine swimmer must hit an opponent with its bite attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it establishes a hold and can rake.

Rake (Ex): Six legs, attack bonus +5 melee, damage 1d4 +1.

Snap Turn (Ex): A brine swimmer can change direction quickly once each round as a free action. It can turn 180 degrees without expending any of its swim speed and can even use the run action after executing such a turn.

Skills: A brine swimmer has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line

Dire Eel

Large Animal (Aquatic)
Hit Dice: 6d8+15 (42 hp)
Initiative: +5
Speed: Swim 30 ft. (6 squares)
Armor Class: 13 (–1 size, +1 Dex, +3 natural), touch 10, flat-footed 12
BaseAttack/Grapple: +4/+12
Attack: Bite +8 melee (1d8+6)
Full Attack: Bite +8 melee (1d8+6)
Space/Reach: 10 ft./5 ft.
Special Attacks: Attach
Special Qualities: Low-light vision, scent
Saves: Fort +7, Ref +6, Will +3
Abilities: Str 19, Dex 13, Con 14, Int 1, Wis 12, Cha 2
Skills: Hide +1 (+5 in coral, rock, or kelp), Listen +5, Spot +6, Swim +12
Feats: Improved Initiative, Toughness, Weapon Focus (bite)
Environment: Warm aquatic
Organization: Solitary or pair
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 7–12 HD (Large); 13–18 HD (Huge)
Level Adjustment: —

The dire eel is a moraylike animal of unusual size. It can reach lengths of 20 feet or more and weigh up to 500 pounds. It resembles its smaller relations in other respects.

Attach (Ex): If a dire eel hits with its bite attack, it uses its powerful jaws to latch onto the opponent’s body and automatically deals bite damage each round it remains attached. An attached eel loses its Dexterity bonus to AC and has an AC of 12. An attached eel can be struck with a weapon or grappled itself. To remove an attached eel through grappling, the opponent must achieve a pin against the creature.

Skills: Dire eels have a +4 racial bonus on Hide checks, which improves to +8 in areas of coral, rock, or heavy kelp. An eel has a +8 racial bonus on any Swim check to perform a special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

Monstrous Scorpion, Large

CR 4

Janni

Piranah Swarm

Tiny Animal (Aquatic, Swarm)
Hit Dice: 8d8+11 (47 hp)
Initiative: +6
Speed: Swim 40 ft. (8 squares)
Armor Class: 15 (+2 size, +2 Dex, +1 natural), touch 14, flat-footed 13
BaseAttack/Grapple: +6/—
Attack: Swarm (3d6)
Full Attack: Swarm (3d6)
Space/Reach: 10 ft./0 ft.
Special Attacks: Distraction
Special Qualities: Half damage from slashing and piercing weapons, low-light vision, scent, swarm traits
Saves: Fort +7, Ref +8, Will +3
Abilities: Str 4, Dex 15, Con 12, Int 1, Wis 12, Cha 2
Skills: Hide +10, Listen +9, Spot +8, Swim +5
Feats: Alertness, Improved Initiative, Toughness
Environment: Warm aquatic
Organization: Solitary or school (2–4 swarms)
Challenge Rating: 4
Treasure: None
Alignment: Always neutral
Advancement: None
Level Adjustment: —

The water boils with small, darting fish, each armed with a jawful of razor-sharp teeth.One of the most feared denizens of warm aquatic environments is the piranha swarm, capable of devouring even a Large creature with amazing quickness.

Combat

Due to a piranha’s unusually strong jaws and sharp teeth, piranha swarms deal more damage than a swarm of their Hit Dice normally would.

Distraction (Ex): Any living creature vulnerable to the piranha swarm’s damage that begins its turn with a swarm in its square is nauseated for 1 round; a DC 15 Fortitude save negates the effect. Even with a successful save, spellcasting or concentrating on spells within the area of a swarm requires a Concentration check (DC 20 + spell level). Using skills requiring patience and concentration requires a DC 20 Concentration check. The save DC is Constitution-based.

Swarm Traits (Ex): See page 316 of the Monster Manual.

Skills: A piranha swarm has a +8 racial bonus on any Swim check to perform a special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

CR 5

Hieracosphinx

Manticore*

CR 6

Hippopotamus

Large Animal
Hit Dice: 8d8+40 (76 hp)
Initiative: -1
Speed: 20 ft. (4 squares), swim 20 ft.
Armor Class: 14 (–1 size, –1 Dex, +6 natural), touch 8, flat-footed 14
Base Attack/Grapple: +6/+17
Attack: Bite +12 melee (2d6+10)
Full Attack: Bite +12 melee (2d6+10)
Space/Reach: 10 ft./5 ft.
Special Attacks: —
Special Qualities: Hold breath, scent
Saves: Fort +11, Ref +5, Will +3
Abilities: Str 24, Dex 9, Con 20, Int 2, Wis 12, Cha 3
Skills: Listen +7, Spot +6, Swim +15
Feats: Improved Bull Rush, Improved Overrun, Power Attack
Environment: Warm plains and forests (rivers)
Organization: Solitary, pair, or herd (10–15)
Challenge Rating: 6
Alignment: Always neutral
Advancement: 9–16 HD (Large); 17–24 HD (Huge)
Level Adjustment: —

Sometimes known as the river horse, the hippopotamus is an immense mammal usually found in or near rivers, ponds, and lakes. It spends most of its daylight hours wallowing in mud or lounging in water to keep its skin from drying out. The typical river hippo has eyes on the top portion of its head (rather than the sides), so that it can see above water as it fl oats. Its large nostrils close tight when it submerges, and it can hold its breath for several minutes at a time. A hippopotamus can even sleep while submerged.

Combat

Hippopotami are often brutally territorial and do not hesitate to attack any thing they perceive as a threat. Their powerful, tusklike incisors can slice through wood and even thin metal with ease.

Hold Breath (Ex): A hippopotamus can hold its breath for a number of rounds equal to 8 × its Constitution score before it risks drowning.

Skills: A hippopotamus has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line

CR 7

Criosphinx

Monstrous Scorpion, Huge

CR 8

Archelon (Giant snapper)

Huge Animal (Dinosaur)
Hit Dice: 12d8+84 (138 hp)
Initiative: –2
Speed: 10 ft. (2 squares), swim 20 ft.
Armor Class: 21 (–2 size, –2 Dex, +15 natural), touch 6, flat-footed 21
BaseAttack/Grapple: +9/+26
Attack: Bite +16 melee (2d6+13)
Full Attack: Bite +16 melee (2d6+13)
Space/Reach: 15 ft./10 ft.
Special Attacks: —
Special Qualities: Hold breath, low-light vision
Saves: Fort +16, Ref +2, Will +5
Abilities: Str 28, Dex 7, Con 22, Int 2, Wis 13, Cha 7
Skills: Listen +11, Spot +6, Swim +17
Feats: Great Fortitude, Toughness (×4)
Environment: Warm aquatic
Organization: Solitary or pair
Challenge Rating: 8
Treasure: None
Alignment: Always neutral
Advancement: 13–24 HD (Huge); 25–36 HD (Gargantuan)
Level Adjustment: —

This huge, flat turtle is easily 15 feet from nose to tail, with a powerful beaked jaw. Its feet are large, paddlelike flippers.

The archelon is a large, primitive sea turtle. While it often feeds on floating carrion or shellfish it digs up out of the mud, it is highly aggressive and is not afraid to come up out of the water in order to reach a meal on shore.

Combat

The archelon attacks with a snap of its oversized jaws.

Hold Breath (Ex): An archelon can hold its breath for a number of rounds equal to 10 × its Constitution score before it risks drowning. For a typical archelon, this is 220 rounds, or 22 minutes.

Skills: An archelon has a +8 racial bonus on any Swim check to perform a special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

Gynosphinx

Tyrannosaurus*

CR 9

Androsphinx

Encounters by CR

CR	Wildlife Encounters	Neighbor Encounters
<0	1 jackal	1 locathah, 1 merfolk
1	2-4 giant fire beetles, 2-4 giant leeches, 2 small diving spiders, 2 small monstrous scorpions, 1 hyena, 1 leech swarm, 1 medium monstrous scorpion	2 locathah, 2 merfolk
2	8-9 tiny diving spiders, 8-9 tiny monstrous scorpions, 5-7 giant fire beetles, 5-7 giant leeches, 5-7 jackals, 3-4 small diving spiders, 3-4 small monstrous scorpions, 2 hyenas, 2 leech swarms, 2 medium monstrous scorpions, 1 cheetah, 1 crocodile	3-4 locathah, 3-4 merfolk
3	10-13 tiny diving spiders, 10-13 tiny monstrous scorpions, 8-10 giant fire beetles, 8-10 giant leeches, 8-10 jackals, 5-6 small diving spiders, 5-6 small monstrous scorpions, 3 leech swarms, 3 medium monstrous scorpions, 1 brine swimmer, 1 dire eel, 1 large monstrous scorpion	1 merfolk brd3
4	14-16 tiny diving spiders, 14-16 tiny monstrous scorpions, 11 giant fire beetles, 11 giant leeches, 11-12 jackals, 7-9 small diving spiders, 7-9 small monstrous scorpions, 4 leech swarms, 4 medium monstrous scorpions, 2 cheetahs, 1 piranah swarm	1 Janni
5	10-11 small diving spiders, 10-11 small monstrous scorpions, 5 medium monstrous scorpions, 3 cheetahs, 2 dire eels, 2 large monstrous scorpions, 1 hieracosphinx, 1 manticore
6	7-9 hyenas, 4 cheetahs, 3 large monstrous scorpions, 2 Janni, 2 piranah swarms, 1 hippopotamus
7	10-13 hyenas, 5 cheetahs, 6 crocodiles, 4 large monstrous scorpions, 3 Janni, 3 piranah swarms, 2 hieracosphinxes, 2 manticores, 1 huge monstrous scorpion	1 criosphinx, small locathah patrol (11-13 + 2x war3 + 1x ftr3), small merfolk patrol (11-13 + 2x war3 + 1x brd3)
8	14-16 hyenas, 7-9 crocodiles, 6 brine swimmers, 5 large monstrous scorpions, 4 Janni, 4 piranah swarms, 3 hieracosphinxes, 3 manticores, 2 hippopotami, 1 archelon, 1 tyrannosaurus	1 gynosphinx, med locathah patrol (11-14 + 2x war3 + 1x ftr4-6), med merfolk patrol (11-14 + 2x war3 + 1x brd4-6)
9	10-11 crocodiles, 7-9 brine swimmers, 4 hieracosphinxes, 4 manticores, 2 huge monstrous scorpions	1 androsphinx, 5 Janni, large locathah patrol (15-20 + 2x war3 + 1x ftr6), large merfolk patrol (15-20 + 2x war3 + 1x brd6)