Vine Horror (CR 4)

Medium Plant (Aquatic)
Alignment: Always neutral evil
Initiative: +0; Senses: low-light vision, Listen +3, and Spot +3
Languages: Sylvan

AC: 18 (+8 natural), touch 10, flat-footed 18
Hit Dice: 5d8+20 (42 hp); DR: 5/bludgeoning
Fort +8, Ref +1, Will +2
Speed: 30 ft., swim 20 ft.
Space: 5 ft./5 ft.
Base Attack +3; Grapple +7
Attack: Slam +7 melee
Full Attack: 2 slams +7 melee
Damage: Slam 1d6+4
Special Attacks/Actions: Animate vines
Abilities: Str 18, Dex 10, Con 19, Int 9, Wis 13, Cha 10
Special Qualities: Half damage from piercing and slashing, malleability, plant traits
Feats: Alertness; Blind-fight
Skills: Hide +15*, Listen +3, Spot +3, and Swim +16
Advancement: 6-7 HD (Large); 8-16 HD (Huge)
Climate/Terrain: Any swamp or aquatic
Organization: Solitary or colony (2-12)
Treasure/Possessions: -

Source: Fiend Folio

Animate Vines (Sp): A vine horror can use this ability to animate any single vine or similar kind of plant life within 90 feet. An animated vine fights as an assassin vine in all respects. An animated vine loses its ability to fight if the vine horror that animated it is incapacitated or moves out of range.

Malleability (Ex): Because of a vine horror's unusual body structure, it can compress its body enough to squeeze through a 1-inch-wide crack. Cracks and similar openings that are 1 inch or more in width do not slow the vine horror at all.

Skills: Vine horrors have 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. *Vine horrors have a +15 racial bonus on Hide checks in swamps or other areas with noticeable concentrations of algae.

Vine horrors often attempt to hide in shallow, algae-filled water, where they then animate trees to attack foes one at a time. Unlike treants and similar creatures, vine horrors care nothing for the trees they animate or the swamps they inhabit.

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.