Abominations are a variant of the human-based Husks created by the Reapers. They appear in Mass Effect 2 and in the multiplayer mode of Mass Effect 3 under the command of the Collectors who deploy them as suicide troops.
Abominations are distinguishable from Husks by the red glow of their cybernetic components. In battle, they will charge enemies much like Husks do, but after grappling to a target they will explode, killing themselves and the target. If an Abomination is critically wounded then it will detonate prematurely.