He appeared in the second issue. After Skull Face attacks Weirdbeard, McCaw captures the skeletal Madball. The two then get the children and the rest of the Madballs to surrender by threatening to harm Skull Face. Captain Weirdbeard then reveals he is after pirate booty buried in the India Incas by Peg Leg Peg. In the end, Weirdbeard and McCaw are defeated by the Madballs and Shocktopus and are forced to do chores for Peg Leg Peg. McCaw hasn't been seen since.
McCaw apparently likes chocolate chip cookies, as mentioned that he'd prefer them, but would be glad to have a chunk of Skull Face when the Madball was held hostage.