Siege Larva (5e Creature)
From D&D Wiki
Medium beast, unaligned
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (1d10 + 3) piercing damage.
Siege larvae are immature siege beetles that are always hungry. After five months of near-continuous eating, the larva becomes a pupa and matures over the course of another two months. During this time, the pupa is immobile and incredibly vulnerable, relying on finding a safe place, such as a cave, to pupate in, though if the pupa is disturbed it can vibrate its body to create a loud noise to frighten off potential predators.