Sloth is the homunculus created by Edward and Alphonse Elric's failed attempt to resurrect their mother. Her body holds the form of water.
Tragedy turns to Pain
Both the Elric brothers Edward Elric, and Alphonse Elric loved their mother Trisha very much from the start. When Hoenheim left the family in search of a cure for his rotting body and left no explanation to the boys Edward believed he had abandoned his mother. Because of Hoenheim dissapearing for a long time Trisha raised the boys by herself. From the day Edward was little to the fights between the two brothers. Watching as the brothers could transmutate things like their father. Even when Winry lost her parents she along with the boys came to comfort her. Truly Trisha was loved and truly she would be missed. One particular day it began to rain suddenly so the boys went home early from the river only to find their mother callapsed with the vegatables she was preparing. Ed and Al could only watch as their mother got weaker by the day until she had prepaered final arrangements for the boys. The Rockwells' along with Ed and Al watched as their mother passed away. Both brothers cried wondering how they would make it without her. Edward was convinced that hed bring his mother back no matter the cost. Both of them began to study their fathers notes on Human Transmutation however they were unable to fully comprehend the notes. Thats when they met Izumai at first she refused to teach the boys about alchemy but hearing that they were orphanned she couldnt bring herself to say no so she taught the boys. She even went as a far as testing them before truly teaching them. Upon return to their home Both Ed and Al deciphered the notes on Human Transmutation. Using their fathers Transmutation circle along with the elemental ingrediants found in a human they attempted to bring Trisha back. At first the transmutation began to break down the elements and recreate them as in an ordinary transmutation. But then the transmutation energy turned purple and soon both brothers were taken in by the transmutation. In the end the thing they brought back wasnt their mother but rather a large clump of meat that was some how alive, a Homunculus. The Elric brothers abandoned it to go seek help soon after Lady Dante apeared offering it Red Stones. Because of this the Homunculus survived. Lady Dante continued to feed it Red Stones until the Homunculus took on the form of Trisha. Due to the Red Stones it even retained some of her memories. Lady Dante named her Sloth, even giving her a job in the military as the Fuhrer's secretary under the name Julia Dugles. Despite having Trisha's memories Sloth detested the idea of loving the boys for making her incomplete. She still had motherly instincts and even took in Wrath as if he were her child. She was eventually killed when Wrath merged with her body after taking in her "true" body parts and not realizing it. Edward reconposed her elemental structure intol Ethinol and she evaporated into the air but not before giving into her motherly instinct telling the boys to clean up after themselves. Whether she did this out of love or to torment the Elrics even more remains unclear.