Roa

Roa is one of the human chimeras associated with Greed's gang out of Devil's Nest. He is a rather large man and appears to have been alchemically combined with an ox. Roa boasts high strength while sacrificing speed, but is rather proficient in both hand-to-hand combat and the use of his trademark sledgehammer. He also has the curious ability to morph from his human form to his even larger, more powerful ox-man form and is the first chimera in the series to do so. He appears in the Ishval flashbacks as an enlisted soldier during the civil war and was presumably injured to the point that he was removed from the battlefield to be a part of human testing.

In the manga
Roa first appears in chapter 26 when he, Dorchet and Martel are ordered by Greed to kidnap Alphonse Elric in Dublith so that the Homunculus may learn the secrets of the boy's armor body and apparent immortality. He is too slow to catch Alphonse during the chase, but is the one who takes the boy down after Martel impedes his movements from inside. Roa is also the henchman charged with helping Greed to prove his immortal and regenerative properties, taking off his boss' head with a sledgehammer upon receiving the Homunculus' silent signal.

When King Bradley storms into Devil's Nest with a regiment of soldiers, Roa takes charge of the counteroffensive and attempts to make a path through which his comrades may escape, but is cut off by Major Armstrong, whom he recognizes from the Ishval Civil War. Aware that he is outmatched by the alchemist's powers, Roa transforms and takes Armstrong on in a blood-boiling monster melee, which only ends when King Bradley himself intervenes, cutting the chimera down. Roa later proves to have survived the attack and makes his way to where Bradley and Greed are fighting, attempting to rescue his boss, but is struck by Bradley again, this time fatally.

2003 anime
In the first anime series, Roa makes his first appearance as one of the test subjects of Laboratory 5 who are released when the facility starts to crumble. He joins up immediately with Greed and the others to escape. Roa is part of the anime's operation to kidnap Alphonse from outside Dante's residence, but when Major Armstrong cuts off their route, Roa is forced to hold him off, first by fighting him, then by destroying the sewer wall to create a barricade when he loses. Roa escapes to the forest with Greed, Dochet, Martel and Al, but Lust and Gluttony arrive and threaten to kill Greed. Roa and Dorchet attempt to fight them so as to offer Greed a getaway, but are killed in the effort.

In the Conqueror of Shamballa movie, a real world version of Roa is seen as one of the scientists working with Alfons Heiderich.

Trivia
Like Martel and Dorchet, Roa is named after a brand of fine liquor.