Strangle Weed (CR 3)

Large Plant (Aquatic)
Alignment: Always neutral
Initiative: +0; Senses: blindsight 30 ft. and Listen +5

AC: 14 (-1 size, +5 natural), touch 9, flat-footed 14
Hit Dice: 4d8+12 (30 hp)
Fort +7, Ref +1, Will +2
Speed: 5 ft.
Space: 10 ft./10 ft. (20 ft. with frond)
Base Attack +3; Grapple +11
Attack: Slam +7 melee
Full Attack: Slam +7 melee
Damage: Slam 1d6+6
Special Attacks/Actions: Constrict 1d6+6, improved grab
Abilities: Str 18, Dex 10, Con 16, Int 2, Wis 12, Cha 6
Special Qualities: camouflage, plant traits, resistance to fire 10
Feats: Power Attack, Weapon Focus (slam)
Skills: Listen +5 and Move Silently +3
Advancement: 5-9 HD (Large); 10-12 HD (Huge)
Climate/Terrain: Temperate and warm aquatic
Organization: Solitary or patch (2-4)
Treasure/Possessions: 50% coins; 1/10th goods; 1/10th items

Source: Converted

Strangle weed lies still until prey comes near. It then lashes out with its fronds, attempting to grapple its foes.

Grappled foes are either squeezed until they die or held underwater until they drown.

Constrict (Ex): A strangle weed deals 1d6+6 points of damage with a successful grapple check.

Improved Grab (Ex): To use this ability, a strangle weed must hit with its slam attack. It can then attempt to start a grapple check without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Blindsight (Ex): Strangle weeds have no visual organs but can ascertain all foes within 30 feet using sound, scent, and vibration.

Camouflage (Ex): Since a strangle weed looks like normal seaweed when at rest, it takes a DC 20 Spot check to notice it before it attacks. Anyone with ranks in Survival or Knowledge (nature) can use one of those skills instead of spot to notice the plant.

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.