Giant Centipede is a Small beast with unaligned alignment and Challenge Rating 1/4 in the 2014 SRD. This stat block includes AC 13, 4 hit points, speeds, traits, and actions.
Bite - Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 4 (1d4 + 2) piercing damage, and the target must succeed on a DC 11 Constitution saving throw or take 10 (3d6) poison damage. If the poison damage reduces the target to 0 hit points, the target is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.