Thief Bug

Thief Bug is a kind of bug that is commonly seen in a damp, dark places. It moves very fast and tends to steal items dropped on the ground. The undeveloped version of the Thief Bug. Even as babies, they're pretty disgusting. Dirty, filthy creatures that tend to work in swarms. Whatever you do, don't let them pollute the Prontera Culverts; it'll be a disaster.

Morphology
This is a diagram of this monster's life cycle.

Ragnarok Online II
In RO2, the Thief Bug comes in several varieties:
 * Thief Bug
 * Thief Bug Larva
 * Baby Thief Bug
 * Lesser Thief Bug
 * Flying Thief Bug
 * Swamp Thief Bug
 * Mutant Swamp Thief Bug