Monstrous Scorpion, Medium (CR 1)

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

AC: 14 (+4 natural), touch 10, flat-footed 14
Hit Dice: 2d8+4 (13 hp)
Fort +5, Ref +0, Will +0
Speed: 40 ft.
Space: 5 ft./5 ft.
Base Attack +1; Grapple +2
Attack: Claw +2 melee
Full Attack: 2 claws +2 melee and sting -3 melee
Damage: Claw 1d4+1, sting 1d4 and poison
Special Attacks/Actions: Improved grab, constrict 1d4+1, poison
Abilities: Str 13, Dex 10, Con 14, Int -, Wis 10, Cha 2
Special Qualities: Vermin
Skills: Climb +5, Hide +4, and Spot +4
Advancement: 3-4 HD (Medium-size)
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: 6 feet long, 3 feet wide* and 6 inches 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.