Originally posted by AugustusKron:

i mean if it's really an "abomination" i guess it's been animated by some evil power, so it should take some extra damage from silver

I think your guess is incorrect. Naturally occurring animals are immune to spirit damage. Boar, deer, and wolves take no spirit damage. Creatures which have been alive, died, and are now reanimated do take spirit damage.

Nothing indicates that an abomination ever died. It may be a live tree imbued with the ability to move quickly. I think an abomination is more akin to a stone golem. Stone golems are basically animated rocks. They never died and so are not undead either.