Eyeball monsters

Eyeballs of many varieties have been found in Castlevania games.

The Ghostly Eyeball in Castlevania II: Simon's Quest floated through the air towards the hero slowly similar to a ghost in other Castlevania games.

Big Eyeballs (plain eyeballs which bounced and/or rolled) appeared in Haunted Castle (where they bounced) and Castlevania: The Adventure, Castlevania II: Belmont's Revenge, and Castlevania: The Adventure ReBirth.

A floating lidded Fire Eye moved along a horizontal line and dripped acid appeared in Castlevania III: Dracula's Curse (where it is also called a "Big Eye") and Super Castlevania IV.

The most common eyeball found in modern games are the Peeping Eyes and their variant Bugbear. These are eyeballs with lids and long retina chains.

Particularly large eye monsters include the Peeping Big and Dogether. Castlevania: Symphony of the Night featured a giant eyeball that looked at you from the background in the Marble Gallery, though you never fought it.