Mr. Fossey is the unhinged first mate of Captain LeChimp aboard The Sea Cucumber, which itself had a crew entirely made of monkeys.
Mr. Fossey believed he could hear the voice of his captain, despite nobody else being able to. He had habit of hearing his master's call just as he was about to say his name. This meant many assuming he worked for the dreaded pirate LeChuck.
He believed that the captain and his crew would use the golden statue of Elaine Marley they stole from the beach to buy an entire fleet of ships, and become the ultimate terror of the Carribbean.
He was fond of chicken, and occasionally ordered from Blondebeard's Chicken Shoppe.