Unusual Nature. The scavver doesn't require air.
Bite. Melee Weapon Attack: +5 to hit (with advantage if the target is a creature that is missing any hit points), reach 5 ft., one target. Hit:7 (1d8 + 3) piercing damage.
Gray scavvers are 6 feet long and travel in packs. The scent of blood sends them into a feeding frenzy, but wounding one usually weakens it enough to make it break off its attack.