Delmar comes to the only possible conclusion about what has happened to their friend Pete, who seems to have been replaced by a toad after the three escapees lose consciousness after imbibing too much liquor in the company of three musical young women.
Delmar: “Them si-reens done loved ‘im up and turned him into a horny-toad!”
Everett: I’m not sure that’s Pete.
Delmar: Of course it’s Pete! Look at him!… We gotta find some kind of wizard to change him back!”
The lesson is to avoid sirens; they’ll love you up and turn you into a toad every time.