One of the longest running adversaries in the Castlevania franchise, Medusa has appeared in nearly every entry and has never been downgraded to anything less than proper boss status. While she was only a floating head in her first appearance, she gained a body as the series progressed, eventually gaining a serpentine body tens of meters long in Portrait of Ruin.
Medusa's abilities vary wildly depending on the game, but her one ability that almost always remains constant is her ability to turn opponents to stone by sight. In her first chronological appearance in Lament of Innocence she can cry bloody, acidic tears, spew a never ending stream of snakes from her mouth, and drill through the floor with her head-snakes. In later entries, such as Symphony of the Night, she has become proficient with a sword and shield, utilizing them with her other abilities. In Portrait of Ruin Medusa will not only summon floating medusa heads at will, she can also transform her entire body into a gargantian snake.