Barrelor, as he appears in the Rum Deal
Barrelor the Destroyer is supposedly a mighty demon who Pirate Pete claims allied with his half-brother, who had stolen Pete's estates and forced him into exile. Pete describes him as being "mighty, fearsome, tall, deadly, oaken and round". Barrelor supposedely guards Pete's family sword within the Trapped Pit of Barrelor.
In actuality, Barrelor was made up by Pete as part of a tale to help find an adventurer heroic enough to help Captain Braindeath. His description appears to be based on one of the brewer's barrels next to Pirate Pete while he recounts the tale.
He appears as a generic lesser demon in the Rum Deal shanty.