Encounters: Cormyrean Marshes - The Vast Swamp

Muckdweller (CR 1/4)

Tiny Monstrous Humanoid
Alignment: Usually lawful evil
Initiative: +7 (+3 Dex, +4 Improved Initiative); Senses: darkvision 60 ft., Listen +1, and Spot +1

AC: 18 (+2 size, +3 Dex, +3 natural), touch 15, flat-footed 15
Hit Dice: 1/4d8 (1 hp)
Fort +0, Ref +5, Will +1

Speed: 20 ft., swim 20 ft.
Space: 2-1/2 ft./0 ft.
Base Attack +0; Grapple -11
Attack: Bite +5 melee
Full Attack: Bite +5 melee
Damage: Bite 1d3-3
Special Attacks: Squirt

Abilities: Str 4, Dex 16, Con 10, Int 10, Wis 9, Cha 8
Special Qualities:
Feats: Improved Initiative; Weapon Finesse
Skills: Balance +5, Hide +13, Listen +1, Spot +1, and Swim +11
Advancement: 1-2 HD (Tiny); 3 HD (Small)

Climate/Terrain: Temperate marshes
Organization: Solitary or pack (5-20)
Treasure: Standard

Source: Serpent Kingdoms

Squirt (Ex): A muckdweller can squirt a jet of water into the eyes of a target up to 25' feet away. Anyone hit by this attack must make a DC 13 Reflex save or be blinded for 1 round. The save DC is Dexterity-based.

Skills: A muckdweller 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. A muckdweller uses its Dexterity bonus instead of its Strength bonus for Swim checks.

Muckdwellers flee unless cornered or certain of an easy kill. Packs of the creatures lurk below the waterline, waiting in ambush for potential prey. Before closing with a foe, muckdwellers employ their spit attacks to blind their opponents.

Faerûnian Random Encounters by Region and Locale