Gluttony is a homunculus created by Father. Simpleminded, he has a insatiable hunger and can eat anything.
Not much is explained about Gluttony's past. Other then a rumor that he was created to contain the philosophers stone. Like his name his power is Gluttony, he is able to eat through ANY substance including the Philosophers Stone. This is due to Gluttony's special saliva however the saliva only takes on its acidic affect when Gluttony activates it as displayed when he bit Ed's automail but it did not melt or deteriorate at all. Because of his saliva anything he eats never actually makes it far into his stomach, the reason why hes hungery all the time. He also displays a great deal of durability as when Scar destroyed his arm and he displayed no affect to it what so ever. Like all the Homunculi he can regenerate so much so he can come back to life, combined with his other powers Gluttony can be considered a powerful Homunculus and only the strongest of alchemist like Dante can control him, also Hoenheim displayed a level of power when self defending against Gluttony upon seeing this Gluttony retreated and said "scary". His personality is chidish at best as Lust baby sits him even telling him to wipe his mouth after eating. Lust is the only Homunculus that shows kindness towards him. He is not above eating humans, although Lust gets upset at him when eating junk like a screw. Because of being with Lust all the time he has grown a strong bond and when Ed told Gluttony that she died trying to help him he went into shock and did not obey Dante/Envy's orders. To get Gluttony to eat Al, Dante pretended to comfort him only to grab his tongue and release his seal of oroboros. This caused Gluttony to loose his personality and become pure instinct towards eating Dante even commented hed even eat Envy if he didnt stay away. in the end as he was midway with eating Alphonse, Alphonse clapped and used alchemy to destroy the lower jaw of Gluttony's mouth.After which he diffied Dante and used the Philosophers Stone to bring Ed back and in term sacraficed himself. As Dante was going up an elevator Gluttony eats a hole at the bottom of the elevatorand is hungry Dante states "you must be hungry, hold on ill get you something to eat" but Gluttony had lost his human like mind and still attacked Dante. Dante clapped and with that both disapeared when the elevator door opened.