A large colony of seaweed about 20 feet or more in diameter covers the nearby area.
Kelp Devil CR 8
AC 20, touch 8, flat-footed 20 (+12 natural, -2 size)
hp 76 (9d8+36)
Fort +11, Ref +4, Will +5
Defensive Abilities underwater concealment; DR 10/slashing or piercing; Immune electricity, plant traits; Resist fire 10
Speed 30 ft., swim 50 ft.
Melee 6 fronds +13 (1d6+8 plus grab)
Space 15 ft.; Reach 15 ft.
Special Attacks charm touch (DC 18)
Str 26, Dex 10, Con 19, Int 5, Wis 12, Cha 10
Base Atk +7; CMB +17 (+21 grapple); CMD 27 (can’t be tripped)
Feats Great Fortitude, Improved Initiative, Iron Will, Lightning Reflexes, Skill Focus (Perception)
Skills Perception +10, Stealth -2 (+10 in natural environment), Swim +19; Racial Modifiers +12 Stealth in natural environment
Twice per day, on a successful hit with a frond, a kelp devil can affect the opponent as by charm monster (caster level 12th). The creature can make a DC 18 save DC to resist the effects. The save DC is Constitution-based.
The main body of a kelp devil remains submerged even when attacking. This grants it concealment (20% miss chance) against all attacks.
Environment temperate and warm aquatic
Kelp devils are relatives of kelpies and are believed to have once been of that race before being subjected to vile and evil experiments that placed them in their current state. To the casual observer, the kelp devil resembles a large colony of slow moving seaweed about 20 feet in diameter. A closer look reveals six 10-foot long pseudopods extending from its body.
Kelp devils are patient creatures. They lie perfectly motionless until potential prey moves within 10 feet. Once their prey is within range, they strike quickly with their pseudopods, attempting to grab an opponent. Grappled creatures are dragged underwater and drowned. Slain creatures are devoured by the kelp devil.
Kelp Devil from the Tome of Horrors Complete, Copyright 2011, Necromancer Games, Inc., published and distributed by Frog God Games; Author Scott Greene, based on original material by Bruce Cordell.