FoulspawnG 15

Out of all the kill this creature X amount of times achievement, this will be the only one that you can miss in your first playthrough. Foulspawn are creatures that have been effected by the spellplague and are only found in a couple of places. The Rhazzad / Linkletter Spellplague story line and in the zone called The Chasm. For me this unlocked when I went through the Spellplague story line with a second character.