This is from the mini-hardcover book The Comic Book Guy's Guide to Life, just one small speck in the massive Simpsons global merchandising onslaught.
This is from a section on Halloween costumes, and of course it makes sense that The Sea Captain would dress up as Aquaman! (And the show's obsession with crappy old tie-in merchandise is well represented here, by Chief Wiggum's spot-on Dick Tracy movie T-shirt)
This is one of three Aquaman "appearances" in the book, sent to me by F.O.A.M. member Brian "Plaid Stallions" Heiler. Thanks Brian!