Medusa

Medusa is the powerful snake woman that has appeared in nearly every Castlevania game to date. She was supposedly going to make an appearance in the cancelled "Castlevania: Resurrection".

Medusa is a woman with snakes instead of hair, also portraited having a snake tail instead of legs, that has the power to transform its victims into stone. In early games, she was a big flying Medusa Head. Besides the boss, several floating Medusa Heads appear as normal enemies in most games.

Castlevania
This Medusa, called Queen Medusa in the American manual, is a big flying Medusa head that drops snakes on the floor. She gives 3000 points after being defeated.

Haunted Castle
This is the first game to show Medusa's more common "snake body" form.

Castlevania III: Dracula's Curse
Medusa was replaced with the Snake Man Sentinel in the North American release, probably to avoid displaying nudity or sexual connotations.

Super Castlevania IV
Medusa appears as a midboss at the end of the Lake section of Level 2, she doesn't leave an orb to be collected after the battle and the River section continues immediately after facing her.

Castlevania: Rondo of Blood
Medusa appears as the second boss summoned by the dark priest Shaft, a reference to the original Castlevania bosses, in which she was the boss of the second level.

Castlevania: Bloodlines
Elizabeth Bartley takes the form of Medusa at the first phase of the fight with her.

Castlevania: Symphony of the Night
In this game, Medusa wields a sword and a shield, a reference to her Greek origins.

Castlevania Legends
In the Game Boy game Castlevania Legends, Medusa is the sub-boss of the fourth stage.

Castlevania: Lament of Innocence
In Castlevania: Lament of Innocence, Medusa has a number of attacks at her command: She can command the snakes on either side to lunge forward as a sort-of snake punch; she can also do this with both sides in succession for a one-two punch. She can rise into the air and spill a trail of her poisonous blood to keep you away. She can also rise into the air to drop a plethora of smaller snakes onto the ground to overwhelm you. She can, of course, project beams ("Turn to stone!") from her eyes that can temporarily turn you to stone; if successful, she'll roll herself into a giant ball and rebound around the room, a random number of times, to damage you heavily. Finally, when her energy is low, she'll command large stones ("Damn you!") to surround herself before firing them toward you one after another. There are two differences in "Crazy Mode": She'll do the snake punch in seven-step combos, and she'll do a stone gaze as part of the stone-throwing attack.

Trivia
She is voiced by Mary-Elizabeth McGlynn in Lament of Innocence.