Gluttony

Gluttony (Japanese:グラト二ー, Guratonī) is the second homunculus to appear in the series, typically being in the company of Lust. He is a large, simple-minded homunculus whose thoughts rarely stray far from eating. He has powerful jaws, acidic saliva, and can and will eat almost anything. He particularly likes eating people, and the only way he can find enjoyment in a battle is if he believes he can eat his opponent afterwards. A running gag in the manga and anime is asking Lust (or any other Homunculi that he is partnered with, such as Wrath or Envy) if he can eat someone. He also told Wrath that he prefers girls (as in to eat, as he finds them soft and tasty) He also seems to share a bond with his partner Lust.

In the Manga & 2009 anime
Gluttony is the sixth Homunculus created by Father (according to Perfect Guidebook 2 ) and the failed product of Father's attempts to create a Gate of Truth. When activating this gate, Gluttony's stomach opens up, revealing a large eye at its center. His ribs spread out to act as a border for the gate, and then double as large extendable teeth. With these teeth Gluttony can consume everything in his eye's field of vision in an instant, which is then transported to a realm within himself. Artifacts from centuries before the start of the series can be found there, indicating Gluttony's age. Gluttony tries to use this form to kill Roy Mustang, Lust's killer, though he makes the mistake of eating Edward Elric, Ling Yao, and Envy instead. Hoping to make it up to Father, Gluttony takes Alphonse Elric to see him, where Ed and Envy are able to escape to. In the ensuing battle Gluttony runs out of energy and he is no longer able to revive himself. Father takes what remains of his Philosopher's Stone and recharges it. He then gives birth to Gluttony by allowing him to grow off of his own body.

After returning to life, he assists in the kidnapping of Al. After doing battle with Greed/Ling Yao and Lan Fan he is eaten by Pride after Pride observes that he has died too many times, implying he is too weak to bother keeping alive. His last words were him calling out for Lust to save him, saying that it hurts. Gluttony is the second Homunculus to die permanently (after his former partner Lust), though curiously not the second, but third to be featured "flying off to heaven" in the inner spines of the tankoban volume books. The first is the original Greed, who is comically shown ascending to heaven with his deceased subordinates, even though he was just reabsorbed into Father's body as a philosopher's stone to given birth to again.

In the 2003 anime
After Lust's death, Dante transforms Gluttony into a mindless eating machine because his moping over Lust's death was annoying her, an act that ultimately backfires when he eats her. He appears again in Fullmetal Alchemist: Conqueror of Shamballa, having transformed into a large, multi-limbed monster since his appearance in the anime. He exclusively attacks Wrath (Lust's killer) during the movie, giving Alphonse Elric an easy opportunity to use Gluttony to create a gate to the other world. He and Wrath die at the same time and are the fifth and sixth of the Homunculi to die.

Trivia

 * Including the time he was reborn, Gluttony has died more times than any other Homunculus