n medium animal 

Perception +7; low-light vision, scent (imprecise) 30 feet

Skills Acrobatics +6, Athletics +9, Stealth +6

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

AC  18; Fort +9, Ref +8, Will +5

HP 30

Gnashing Grip [R] Trigger A creature grabbed by the giant monitor lizard's jaws fails a check to Escape. Effect The giant monitor lizard's jaws deal 1d6 piercing damage and the triggering creature is exposed to monitor lizard venom.

Speed 30 feet, swim 30 feet

Melee [>] jaws +11, Damage 1d10+3 piercing plus Grab and monitor lizard venom

Lurching Charge [>>] The giant monitor lizard Strides twice and then makes a jaws Strike. If the lizard moved at least 20 feet away from its starting position, it gains a +2 circumstance bonus to this attack roll.

Monitor Lizard Venom (poison) Saving Throw DC 17 Fortitude; Maximum Duration 6 rounds; Stage 1 enfeebled 1 (1 round); Stage 2 1d6 poison damage and enfeebled 2 (1 round)

Bestiary, page 229.