Schmoo

A floating severed head wearing what may be a pillowcase or an execution hood, the Schmoo flies erratically, careening around the room to attempt to hit the hero. It does a surprising amount of Dark damage with each hit, and can be hard to target. They are the only non-Wizard of Oz-themed enemy in the Reverse Library. Very importantly, Schmoos drop the Crissaegrim weapon, although only very rarely. Earning the Crissaegrim essentially makes the entire game easy. Schmoos may have been named after The Schmoo from the Li'l Abner comics, created by Al Capp. The original Schmoos are little white creatures shaped like bowling pins with legs, not resembling the bleeding, rotting heads that are Castlevania Schmoos.

Trivia
Schmoo's Japanese name Kyuu (Q). possibly parody of [Obake no Q-tarō]