The guardian abomination is the Greater Eidolon of Ashtan. When Ashtan declared itself the Seat of Chaos in 691 AF, the Zarathustrian Eagle devolved into the tortured, many-tentacled guardian abomination.
Possessing a vague, humanoid figure, the jaundiced, three-headed creature retains traces of its avian form only in the roc-like visage of two of its mutated heads.