Rascacoon is a small island just north of Kilmaresh. The island inhabitants are called the Rascoohan and migrated to this island from a place called Washingstone. They are under constant attack by the Pirats.
Rascacoon can be accessed through the Pirat Mine and the Exotic Cave Spider Cave, which is accessed from Issavi. It's also possible to take a shortcut there with Eustacio if he trusts you.
Access to the island is obtained through A Pirate's Tail Quest. Most of the quest also takes part here.