Red Sundew (CR 13)

Huge Plant
Alignment: Always neutral
Initiative: -1 (Dex); Senses: woodsense and low-light vision

AC: 11 (-2 size, -1 Dex, +4 natural), touch 7, flat-footed 11
Hit Dice: 15d8+75 (142 hp)
Fort +14, Ref +4, Will +6
Speed: 20 ft.
Space: 15 ft./15 ft.
Base Attack +11; Grapple +15
Attack: 4 slams +18 melee
Full Attack: 4 slams +18 melee
Damage: Slam 2d6+9 plus acid
Special Attacks/Actions: Improved grab, sticky acid
Abilities: Str 29, Dex 8, Con 21, Int 2, Wis 13, Cha 8
Special Qualities: Immunities: Red sundews are immune to fire and acid
plant traits
Feats: Cleave; Great Cleave; Improved Bull Rush; Improved Overrun; Power Attack; Skill Focus (Hide)
Skills: Hide +12
Advancement: 16-28 HD (Huge); 29-45 HD (Gargantuan)
Climate/Terrain: Temperate and warm forests
Organization: Solitary or patch (2-5)
Treasure/Possessions: None

Source: Monster Manual II

Improved Grab (Ex): If a red sundew hits an opponent that is at least one size category smaller than itself with a slam attack, it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity (grapple bonus +28). If it gets a hold, it has the option to conduct the grapple normally, or simply use its tentacle to hold the opponent (-20 penalty on grapple check, but the red sundew is not considered grappled). In either case, each successful grapple check it makes during successive rounds automatically deals slam damage.

Sticky Acid (Ex): A red sundew is coated with a thick, acidic goo. Any creature or object that makes physical contact with the monster is smeared with this sticky acid, which deals 1d6 points of acid damage per round until removed. Thus, any successful hit from or against the red sundew automatically deals acid damage to the opponent or the opponent's weapon, depending upon the point of contact. Sticky acid remains on a creature or object for 1d4+1 rounds. It cannot be scraped off, but it can be washed off with a full-round action and at least 1 gallon of water.

Woodsense (Ex): A red sundew can automatically sense the location of anything within 60 feet that is in contact with vegetation, even objects or creatures that are not in contact with the same vegetation as itself.

Red sundews are aggressive hunters. They attack with their tentacles, wrapping them firmly around prey to prevent escape while the sticky acid that coats their tentacles begins the digestion process. Multiple red sundews often travel together and combine their efforts while hunting. These carnivorous plants flee when more than half their number has been slain.