Plucky Duck and Hamton J. Pig Meet Monster High

Plucky Duck is in Hollywood producing a movie about King Arthur and the Knights of the Round Table, starring himself; also appearing in the film are Hamton Pig, Priscilla Pig, Furrball, Sweetie Pie, Calamity Coyote, Fowlmouth, Fifi La Fume, Elmyra Duff, Montana Max, and Byron Basset. Frankie Stein, Draculaura, Clawdeen Wolf, Cleo de Nile and Sabrina Spellman are watching a television interview in which Plucky is talking about his new movie, when their program is interrupted by a ghoulish being calling himself The Phantom of the Flickers; he announces his intention to destroy every film that Plucky Duck and the company ever made, including their current King Arthur film. Being a huge fan of Plucky, Frankie goes to Hollywood to offer her help, and the other Monster High girls go along with her.

Mayhem ensues when the Looney Tunes and the MH girls first meet, but they eventually settle down and continue filming the movie. But when the Phantom disguises himself as each of MH girls, Daffy and the others then think that they are in league with the Phantom and run off. The Phantom suddenly grabs the film and, disguised as Hauntleroy, tries to escape from MH girls by running through a magic mirror into "Mad Mirror Land" (i.e., the real world). Frankie, Drac, and Wolfie chase after him, and after a cartoonishly slapstick pursuit they bring (or more rather sneeze) the Phantom and the film back to their world.

The Phantom turns out to be Drac’s long-lost uncle Claude Chaney, a formerly famous silent film actor who was acting out of anger over black-and-white films being replaced by color films. Daffy gives Claude a job, the movie wins an award, and the Goolies head for home.