n medium animal 

Perception +7; low-light vision

Skills Acrobatics +8, Athletics +5 (+9 to Climb), Stealth +6

Str +2 Dex +3 Con +1 Int -4 Wis +2 Cha -2

Uncanny Climber A giant gecko's feet allow it to climb virtually any surface, no matter how slick or sheer. If a giant gecko attempts an Athletics check to climb and critically fails, it gets a failure instead.

AC  16; Fort +6, Ref +10, Will +5

HP 20

Speed 30 feet, climb 30 feet

Melee [>] jaws +8, Damage 1d8+2 piercing

Bestiary, page 228.