Boil

Pustule
Pustule is an alternate version of Boil that grows until it bursts into Small Maggots. Fortunately, Pustules take much longer to fully swell up and do not regenerate unlike normal Boils.

If killed quickly, Pustules won't leave any creep or spawn any Small Maggots. Otherwise, upon death, they may leave behind a small pool of damaging green creep and a few Small Maggots.