Fossergrim (CR 5)

Medium Fey (Aquatic)
Alignment: Always neutral
Initiative: +7; Senses: low-light vision and Spot +9
Languages: Common and Sylvan

AC: 18 (+2 Dex, +6 +1 chainmail), touch 12, flat-footed 16
Hit Dice: 5d6+15 (32 hp); DR: 5/iron (in water only)
Fort +4, Ref +7, Will +6
Speed: 30 ft., swim 60 ft.
Space: 5 ft./5 ft.
Base Attack +2; Grapple +4
Attack: Masterwork longspear +3 melee, or masterwork battleaxe +3 melee, or masterwork longbow +6 ranged
Full Attack: Masterwork longspear +3 melee, or masterwork battleaxe +3 melee and masterwork handaxe +3 melee, or masterwork longbow +6 ranged
Damage: Masterwork longspear 1d8+3, masterwork battleaxe 1d8+2, masterwork handaxe 1d6+2, masterwork longbow 1d8
Special Attacks/Actions: True strike (in water only)
Abilities: Str 15, Dex 17, Con 16, Int 12, Wis 15, Cha 18
Special Qualities: Fast healing 5 (in splashing water only), SR 15 (in splashing water only), waterfall dependency
Feats: Improved Initiative; Two-Weapon Fighting
Skills: Diplomacy +13, Heal +9, Hide +10, Knowledge (nature) +10, Sense Motive +9, Spot +9, Survival +9 (+11 in aboveground natural environments), and Swim +17
Advancement: 6-8 HD (Medium-size); 9-15 HD (Medium-size)
Climate/Terrain: Any land
Organization: Solitary
Treasure/Possessions: Standard

Source: Fiend Folio

True Strike (Sp): As long as both a fossergrim and its opponent are standing in the fossergrim's river, the fossergrim gains a +20 insight bonus on attack rolls as if affected by the spell true strike. The distance between the fossergrim and target does not matter, although range increments still apply.

Fast Healing (Ex): When in splashing water, a fossergrim regains lost hit points at the rate of 5 per round. Fast healing does not restore hit points lost from starvation, thirst, or suffocation, and it does not allow a fossergrim to regrow or reattach lost body parts.

Waterfall Dependency (Su): Each fossergrim is mystically bound to a large waterfall and must never stray more than 1,000 feet from it. Any who do become ill and die within 4d6 hours. A fossergrim's waterfall does not radiate magic.

Skills: A fossergrim has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard and can always choose to take 10 on Swim checks, even if distracted or endangered.

A fossergrim prefers to fight from within the cascading sheet of its waterfall (providing at least one-half concealment) and attack with its longspear or longbow. If attacked while caught away from its waterfall, a fossergrim retreats to it as quickly as possible.

Many of its special abilities work only when a fossergrim is standing in "splashing" water. This includes the waterfall itself, plus an area that extends out 2d10x5 feet downstream (or farther for bigger waterfalls).

A fossergrim can be summoned using a summon nature's ally V spell.

Aquatic Subtype

Creatures with the aquatic subtype always have swim speeds and thus can move in water without making Swim checks. An aquatic creature can breathe underwater. It cannot also breathe air unless it has the amphibious special quality.