Giant Ant Lion (CR 5)

Large Vermin
Alignment: Always neutral
Initiative: -1 (Dex); Senses: darkvision 60 ft. and Listen +5

AC: 14 (-1 size, -1 Dex, +6 natural), touch 8, flat-footed 14
Hit Dice: 8d8+24 (60 hp)
Fort +9, Ref +1, Will +3
Speed: 20 ft., burrow 20 ft.
Space: 10 ft./5 ft.
Base Attack +6; Grapple +14
Attack: Bite +9 melee
Full Attack: Bite +9 melee
Damage: Bite 2d8+6 plus poison
Special Attacks/Actions: Constrict 2d8+6 plus poison, improved grab, pit, poison, sand burst
Abilities: Str 19, Dex 8, Con 17, Int -, Wis 12, Cha 7
Special Qualities: vermin traits
Feats: -
Skills: Hide -1* and Listen +5
Advancement: 9-16 HD (Large); 17-24 HD (Huge)
Climate/Terrain: Temperate deserts
Organization: Solitary
Treasure/Possessions: None

Source: Sandstorm

Constrict (Ex): A giant ant lion deals 2d8+6 points of damage with a successful grapple check.

Improved Grab (Ex): To use this ability, a giant ant lion must hit a creature with its bite 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 constrict.

Pit (Ex): The pit of a giant ant lion fills four adjacent 5-foot squares and is 20 feet deep. It isn't hard to recognize, requiring a DC 10 Spot or Survival check to notice. Charging or running characters are not entitled to a check. A creature that does not notice the pit can make a DC 17 Reflex save to avoid falling in.

A creature that falls into the pit begins to slide to the bottom at the rate of 10 feet per round. A DC 17 Climb check is necessary to arrest the slide, and struggling out of the pit requires a DC 22 Climb check.

Poison (Ex): Injury, Fortitude DC 17, initial damage none, secondary damage paralysis 1d6 rounds. The save DC is Constitution-based.

Sand Burst (Ex): A giant ant lion can hurl sand at a struggling creature to knock it from the pit walls. It makes a ranged touch attack; on a hit, the target must make an immediate DC 22 Climb check or slide 10 feet toward the bottom of the pit.

Skills: Giant ant lions have a +8 racial bonus on Hide checks. *This bonus rises to +12 when buried in their sandy pits. They also have a +4 racial bonus on Listen checks.

A giant ant lion finds a dry slope of loose, sandy soil and digs its way in backward, hurling sand out in circles until it has formed a funnel-shaped pit about 20 feet deep. It lurks there and waits for a creature to slide in, then grabs it with lightning speed and paralyzes the prey with its poisonous bite.