In the 17th Century, Count Dracula was reawakened a century after his demise due to fear of him dissipating. His first act upon awakening was causing storm clouds to envelop a nearby church, as well as ambushing a newlywed couple and abducting the bride, Selena, to feast upon her blood, requiring her husband Simon Belmont, of the Belmont Clan, to pursue the fiend to his demon castle.
Dracula eventually encountered Simon at the castle's keep and fought him with his various abilities, including turning into a swarm of bats. Simon managed to destroy the Count's body, although then his soul manifested itself as a giant bat-spewing head, with Simon ultimately eliminating the monster for good and saving Selena.
In Haunted Castle, Dracula changes his pattern by hovering in the air and throwing daggers. He also moves by transforming into a swarm of bats before dashing around the room; this move would also be implemented in many of his later incarnations and would also determine the way later versions of the Giant Bat would travel around a room. Players who reach this far in Haunted Castle will be relieved to know that this time Dracula can be hit anywhere on his body.
When he turns into a giant head, Dracula spews swarms of bats at you and it's important to defeat him quickly before damage builds up.