Medusa Head

Medusa Heads in the Castlevania series are infamous for knocking heroes off of platforms and causing no end of trouble for game players. They are often considered to be one of the most annoying enemies in video game history.

Overview
Spawned from the hair of Medusa, Medusa Heads will fly through the air in an attempt to ram into heroes. They usually appear whenever a hero is trying to cross a hazardous series of platforms. Oddly enough, they also appear in some games where Medusa herself isn't present.

The standard Medusa Head normally just flies in a wave-like pattern, usually making them hard to dodge, but aside from them running into the player, they don't do anything else.

Since the release of Castlevania II: Simon's Quest, another variant was introduced into the series. These Medusa Heads will home-in toward the player instead of flying aimlessly in wave-like patterns. However, this behavior has not been used as often as the first kind, making their most prominent appearances in Castlevania (Nintendo 64) and Legacy of Darkness.

Another time when the basic attack pattern of the Medusa Heads has been altered is in Castlevania: Bloodlines. In the last stage, The Castle Proserpina, Medusa Heads will start appearing while the hero is trying to cross a crumbling bridge. They will appear from the top or the bottom of the screen, stop in mid-air, and shoot a fast fireball toward the hero.

Since the release of Rondo of Blood, a new gold colored variant was introduced. Their behavior remained the same as the blue variant and had no impact on gameplay whatsoever, so they were just added for aesthetic reasons. However, since the release of Symphony of the Night, they were given the ability to petrify any player who touched them. This could be extremely dangerous, as petrification could lead to landing on spikes or in front of other enemies. While the gold colored Medusa Heads are often just called "Medusa Heads", they have also been called Gold Medusas on occasion.

Yet another variant was introduced in Order of Ecclesia, named Gorgon Heads. This variant also has the ability of petrifying the protagonist upon contact; however, they'll only appear after five of the other two kinds combined have been slain. Killing one of these has a 100% chance of leaving a Fidelis Medusa glyph.

Summoning
In some games, the protagonist is able to summon a Medusa Head, either as a quick summon or as a Familiar. A Medusa Head (of varying sizes) will usually shoot beams from its eyes and induce petrification if they connect with an enemy.

Castlevania II: Simon's Quest
Medusa Heads in Simon's Quest behave a bit different than most ones present in the rest of the series. Here, they just home-in toward Simon, not unlike the way ghosts used to do in the original Castlevania. Oddly enough, ghosts in Simon's Quest will now travel in a wave-like pattern, just like Medusa Heads used to do in the first game.

Castlevania: Symphony of the Night
Gold Medusa Heads will not petrify Alucard when he has the Medusa Shield equipped. Instead, they will act exactly like the blue variant.

Castlevania (Nintendo 64) / Castlevania: Legacy of Darkness
Medusa Heads will materialize out of thin air in front of the protagonist. They usually appear when he or she is trying to make a difficult jump over a hazardous area (like poisoned water, spikes or lava), attempting to make contact in mid-air to send him or her to their untimely demise with just one hit. Oddly enough, when they appear they display electric bolts around them, the reason for this is unknown as they don't deal any kind of elemental damage.

Castlevania: Circle of the Moon
In Circle of the Moon, only the normal blue colored type of Medusa Head appears. Despite of this, they have the ability to petrify Nathan upon contact, a feature that only Gold Medusas can do in the rest of the series.

Castlevania: The Arcade
Medusa Heads will try to hinder your progress across narrow walkways in the Clock Tower of Castlevania: The Arcade.

Trivia

 * Medusa Heads, Gorgon Heads and Medusa, all are Greek female creatures called s, despite the fact that in the series, the enemy called Gorgon is inspired by an ox-like mythological creature of Libyan origins.
 * Even though they don't make a true appearance in the Lords of Shadow games, they make a cameo on the carousel wheel in the Toy Maker's Funfair area in Mirror of Fate.