Gluttony

Gluttony is a heavyset, bald figure whose skin runs noticeably darker than the pale complexions of his fellow Homunculi. His eyes are a trait he shares with Sloth: tiny, blank dots rather than proper irises, a quirk that mirrors the pair's similarly dull minds. In his transformed state a vast mouth splits open across his midsection, and an eye resembling the one at the true Gate of Truth stares out from the void within.

Left to himself, Gluttony is placid and remarkably gentle, but the sight of permitted prey can tip him into a feeding frenzy. He constantly asks whichever sibling is minding him for leave to eat, sometimes even posing the question to opponents in the middle of a fight, and admits a preference for devouring girls, whom he finds soft. For all his cannibal habits he behaves like a big, affectionate child, adoring his siblings, greeting the reborn Greed with delight and breaking down at word of Lust's death.

He carries none of the contempt for humanity that drives the other Homunculi, and seems genuinely oblivious to the fact that his meals die for good. His limited wits make him a liability who needs babysitting; alone, he grows lost and unable to decide anything. Yet he is not entirely dim. He nurses a real grudge against Roy Mustang for killing Lust, recalls Lan Fan the instant she attacks him, and identifies the Elrics and others by scent, his memory seemingly bound to his powerful nose. In the 2003 anime his makeup is much the same until Dante strips away his humanity, reducing him to a mindless eating machine that nonetheless still singles out Lust's killer.

As a Homunculus, Gluttony outstrips any human in strength, speed, and durability, and he recovers from nearly anything; decapitation, incineration, and being blown apart all mend within moments. He needs no food, water, or sleep, yet eats without end because hunger is his very nature. His body brews potent digestive enzymes that let him chew through steel and stone, while his senses of taste and smell are sharp enough to read the makeup of a substance or trail a specific person through pitch darkness. His ribcage can fire outward at blinding speed to snatch and swallow targets, even launching him skyward despite his bulk.

Father built Gluttony as a botched attempt to forge a homemade Gate of Truth that would grant unlimited alchemical knowledge. The result is a false gate: the blackness inside him is a sealed pocket lying between reality and the real Gate, an ocean of his victims' blood heaped with everything he has ever eaten. A person trapped there can escape only by transmuting themselves and another swallowed body without altering anything, which forces the genuine Gate open. His distance-swallowing even lets him consume foes from afar, as when he devours Edward, Ling, and Envy at once.

For all his menace, Gluttony is clumsy and lacks the cunning of his siblings, leaning so hard on his immortality that he dies more often than any other Homunculus. After running out of energy against Alphonse near Father's lair, he is absorbed and later regrown, then killed for good by Pride, who devours his weakened brother, making Gluttony the second Homunculus to fall permanently.