Ironthorn (CR 6)

Large Plant
Alignment: Always neutral
Initiative: +0; Senses: blindsense 60 ft. and Spot +13
Languages: No language

AC: 24 (-1 size, +15 natural), touch 9, flat-footed 24
Hit Dice: 9d8+63 (103 hp); DR: 5/bludgeoning or slashing
Fort +13, Ref +3, Will +4
Speed: 10 ft.
Space: 10 ft./5 ft. (15 feet with vines)
Base Attack +6; Grapple +13
Attack: Vine rake +8 melee
Full Attack: 2 vine rakes +8 melee
Damage: Vine rake 1d6+3
Special Attacks/Actions: Impale, improved grab, poison
Abilities: Str 17, Dex 10, Con 25, Int 1, Wis 12, Cha 1
Special Qualities: plant traits
Feats: Ability Focus (poison); Heat Endurance; Improved Heat Endurance; Toughness
Skills: Spot +13
Advancement: 10-18 HD (Large); 19-27 HD (Huge)
Climate/Terrain: Warm deserts
Organization: Solitary
Treasure/Possessions: 1/10th coins; 50% goods; 50% items

Source: Sandstorm

Impale (Ex): An ironthorn deals 2d6+4 points of damage to a grabbed opponent with a successful grapple check. The opponent is pulled deep into the plant's thorny mass and is subject to the plant's poison (see below).

Improved Grab (Ex): To use this ability, an ironthorn must hit with a vine attack. It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it establishes a hold and can impale.

Poison (Ex): Injury, Fortitude DC 23, initial damage paralysis 1d4 minutes, secondary damage 2d4 Con. A victim must save against the secondary damage each minute that it is held in the thorns. The save DC is Constitution-based.

An ironthorn waits for a creature to pass within reach of its feeding vines, which look like its other twisted branches until they lash out. With their extended reach, the vines often take prey by surprise. Once it has grabbed its prey, an ironthorn pulls it deep into its mass of poisonous thorns, where the victim is impaled and left to slowly die. The ironthorn then slowly absorbs the flesh as it rots.