The Abomination is a DLC quest available in Dragon's Dogma.
- "An unspeakable beast has risen in the west. Go and cut it down with all haste, afore it descends on the capital!"
Slay a Gorechimera.
This quest becomes available on Pablos' Inn notice board immediately after slaying The Dragon in The Final Battle.
There is a Gorechimera on the Unusual Beach directly outside Cassardis at this point.
Kill it to complete the quest and obtain an Aneled Cyclops Sigil.
- Slaying any other Gorechimera will also complete the quest.