Ouroboros

Ouroboros refers to the ancient mystical and Alchemical symbol representing a serpent or dragon devouring its own tail, so as to signify infinity and unity. Being a circle, it shows that infinity has neither beginning nor end, while the dragon biting its tail shows that the beginning and end of infinity are the same place. All of the seven main Homunculi in the Fullmetal Alchemist series are presumed to have the mark located somewhere upon their person as if tattooed there, save for Pride in the manga and 2009 anime. This particular Ouroboros displays a winged serpent with its tail in its mouth, creating a circle with its body. Encircled within is a hexagram, which is a symbol often associated with alchemy as well as human creation. One could perceive the Ouroboros as a sort of basis for the Transmutation Circles used in the series and it is possible that the Ouroboros may also symbolize a solar eclipse in some belief structures.



Before learning of their identities as Homunculi, Edward referred to the individuals behind the odd circumstances in Amestris as "Members of the Ouroboros".

In all versions of the story:

 * Lust's Ouroboros is located on her upper sternum, just above her breasts.
 * Gluttony's Ouroboros is located on his tongue.
 * Envy's Ouroboros is located on its left thigh.
 * Greed's Ouroboros is located on the back of his left hand.

In the manga and 2009 anime:

 * Wrath's Ouroboros is located on his left eye (same as Pride in the 2003 anime).
 * Sloth's Ouroboros is located on the back of his right shoulder.
 * Pride is the only Homunculus without an Ouroboros, instead having a circular mark on his true form's forehead.

In the 2003 anime only:

 * Wrath's Ouroboros is located on the sole of his right foot.
 * Sloth's Ouroboros is located above her left breast, presumably at the heart.
 * Pride's Ouroboros is located on his left eye (same as Wrath in the manga and 2009 anime).

Trivia

 * The word Ourboros is derived from the Greek words "ουρά" + "βορά", tail + eating. This could be roughly translated as "he who eats his tail", matching the imagery of a dragon eating its own tail.
 * As seen from the images, the manga version of the Ouroboros is slightly different from the anime versions. The hexagram that encompasses the center is changed to a more stylized hexagram, presumably to avoid any kind of religious references.
 * In the first anime, Homunculi can be reduced to a state where they are completely dominated by their sin if their tattoo is removed. This is seen with Gluttony when his tattoo is removed and he becomes a mindless eating machine.
 * In the 2003 anime and movie, Envy was an example of a living Ouroboros due to his shape-shifting ability (more specifically as a dragon).