The Gremlin is an enemy in the Castlevania series. They are creatures who love to fiddle with machinery.
The gremlin is a folkloric mischievous creature that causes malfunctions in aircraft or other machinery. While depictions of these creatures vary, past findings present these beings to be similar to the Chupacabras, with spiky backs, large eyes, and small clawed frames that feature sharp teeth.
The gremlins' mischievous nature is similar to those of English folkloric imps, while their inclination to damage or dismantle machinery is more modern.
In Circle of the Moon, Gremlins appear as winged little devil-like creatures that fly from one side of the screen to the other in endless numbers. They come armed with a spear, and sometimes they may make a brief stop in midair and hurl it toward the player, continuing their way afterward.
They start appearing in the first level, the Catacomb, and frequently drop Wrist Bands, which is the first STR boosting item available to the player in the game (STR +5), making them worth farming until the player has acquired at least a couple of these.
The Gargoyle is a palette swap of the Gremlin, albeit stronger (with double its stats).
In Aria of Sorrow, the Gremlin's appearance is more draconian-like (it is just a palette swap of the Gargoyle). Unlike its previous incarnation where they appeared in endless numbers, this time their numbers are fixed to the room they appear in. It flies about, trying to position itself above and at an angle from the player, and then makes a swoop at them in an attempt to inflict contact damage.