Battlebriar (CR 15)

Huge Plant
Alignment: Usually neutral
Initiative: -2 (Dex); Senses: darkvision 60 ft. and low-light vision

AC: 30 (-2 size, -2 Dex, +24 natural), touch 6, flat-footed 30
Hit Dice: 25d8+200 (312 hp)
Fort +22, Ref +6, Will +10
Speed: 30 ft.
Space: 15 ft./10 ft.
Base Attack +18; Grapple +37
Attack: Slam +28 melee
Full Attack: 4 slams +28 melee
Damage: Slam 2d6+11/19-20
Special Attacks/Actions: Impale, improved grab, thorn volley, trample 2d6+16
Abilities: Str 32, Dex 6, Con 27, Int 5, Wis 10, Cha 7
Special Qualities: plant traits, resistance to electricity 20 and fire 20, thorn field
Feats: Awesome Blow; Cleave; Great Cleave; Improved Bull Rush; Improved Critical (slam); Improved Natural Attack (slam); Iron Will; Power Attack; Weapon Focus (slam)
Skills: Hide +18*
Advancement: 26-50 HD (Huge)
Climate/Terrain: Temperate forests
Organization: Solitary
Treasure/Possessions: None

Source: Monster Manual III

Impale (Ex): Whenever a battlebriar successfully starts a grapple with a Medium or smaller creature, there is a chance that the creature will become impaled on one of the thorns. After the grapple has begun, a battlebriar can attempt another grapple check as a free action to impale the creature on its thorns.

An impaled creature is helpless until it beats the battlebriar in an opposed grapple check. As long as the only creatures that it is grappling with are impaled, a battlebriar is not considered grappled (the battlebriar does not lose its Dexterity bonus to AC, still threatens an area, and can use its remaining attacks against other opponents). When making grapple checks against impaled creatures, a battlebriar takes a -20 penalty on grapple checks.

Improved Grab (Ex): To use this ability, a battlebriar must hit with its slam attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity.

Thorn Volley (Ex): Battlebriars grow and shed their thorns at an incredible rate, and by rearing up on their hind legs and snapping their bodies forward, they can launch a deadly volley. As a standard action, a battlebriar can launch a volley of thorns, centering the volley anywhere within 60 feet. The thorns deal 8d6 points of piercing damage to all creatures within a 10-foot radius (Reflex DC 33 half). The save DC is Strength-based.

Trample (Ex): Reflex half DC 33. The save DC is Strength-based.

Thorn Field (Ex): The thorns on a battlebriar's body protrude into the area surrounding the creature, causing several effects on creatures moving through a battlebriar's threatened area. A battlebriar can make up to four attacks of opportunity each round. (Unlike the Combat Reflexes feat, this ability does not allow a battlebriar to make attacks of opportunity while flat-footed.) In addition, the DCs for Tumble checks to move through a battlebriar's threatened area or through the squares that it occupies increases by 10. Creatures three or more size categories smaller than a battlebriar cannot freely move through the area that a battlebriar occupies.

Skills: Despite its size, a battlebriar blends well with its surroundings, and it gains a +8 racial bonus on Hide checks in aboveground, natural environments.

A battlebriar is neither smart enough nor inventive enough to give much thought to tactics. It moves toward its foes with ponderous steps, launching volleys of thorns if its foes are too mobile to catch. Although slow-thinking by human standards, a battlebriar is at least perceptive enough to use its various attack forms to its best advantage, trampling large groups of smaller foes, using its volleys of thorns against fleeing enemies, and moving close to foes who engage in melee combat so as to expose them to its deadly thorns. More by accident than strategy, battlebriars have developed one fighting technique that is extremely effective against Medium and smaller foes. A battlebriar moves up to its foe and uses its Awesome Blow feat, earning a free attack of opportunity against its foe if the feat is successful because the affected creature is pushed through a battlebriar's threatened area.