S2·E8 Urban Legend

Aldo has a nightmare about Quack the Ripper, a monstrous duck that shows up every midnight. He tells his friends that Quack is feared by all the alligators in Swampwood, so Ed comes up with an idea to make Waddle dress up like Quack. Something goes wrong and Waddle is almost eaten until the real Quack shows up and scares off the alligators.