Throwing a Medusa Head will immediately make it fly back and forth in its infamous wave-like pattern until it eventually flies off-screen. It deals 11% damage to any opponent that touches it. Medusa Head is a rather unique throwing item in the sense it can only be thrown sideways, attempting to throw it upwards and downwards will simply activate it to move in the direction the character was facing prior throwing it.
Medusa Heads originate from the very first Castlevania game. They are spawned from the hair of Medusa, they are well-known enemies in the series due to their tendency to fly through the air in a wave-like pattern attempting to ram into the player, making them rather unpredictable and hard to dodge, especially if they come in great numbers toward the player. They usually appear in areas where there is a hazardous series of platforms. They may also appear in games where Medusa herself is not present.
Though many variants of the Medusa Head exist in the multiple Castlevania titles, SSF2 uses the aforementioned standard Medusa Head from the first game.