Monstrous Scorpion, Large (CR 3)

Large Vermin
Alignment: Always Neutral
Initiative: +0; Senses: darkvision 60 ft., tremorsense 60 ft., and Spot +4


AC: 16 (-1 size, +7 natural), touch 9, flat-footed 16
Hit Dice: 5d8+10 (32 hp)
Fort +6, Ref +1, Will +1
Speed: 50 ft.
Space: 10 ft./5 ft.
Base Attack +3; Grapple +11
Attack: Claw +6 melee
Full Attack: 2 claws +6 melee and sting +1 melee
Damage: Claw 1d6+4, sting 1d6+2 and poison
Special Attacks/Actions: Improved grab, constrict 1d6+4, poison
Abilities: Str 19, Dex 10, Con 14, Int -, Wis 10, Cha 2
Special Qualities: Vermin
Feats:
Skills: Climb +8, Hide +0, and Spot +4
Advancement: 6-9 HD (Large)
Climate/Terrain: Warm desert
Organization: Solitary or colony (2-5)
Treasure: None

Source: Monster Manual

Monstrous scorpions are vicious predators that make unnerving scuttling noises as they speed across dungeon floors. A monstrous scorpion has a low, flat body: 10 feet long, 5 feet wide* and 1-1/2 feet high**.
*The number includes the scorpion's body and its legs; the actual body width is about a third of the total.
**The number indicates the height of the creature's body; the creature's stinger usually is held about as high off the ground as the creature is wide.