Daffy Duck's Quackbusters is a 1988 Looney Tunes film with a compilation of classic Warner Bros. Cartoons shorts and animated bridging sequences, starring Daffy Duck. It is the final Looney Tunes project in which Mel Blanc provided the voices of the characters. The film was released to theaters by Warner Bros. Pictures on September 24, 1988.

The film begins with the cartoon Daffy Dilly. Street corner salesman Daffy tries to make a pitch to reclusive billionaire and "ailing buzzsaw baron" J.P. Cubish (a dog)---who has offered wealth to anyone who can make him laugh---only to be stymied by Cubish's butler (also a dog). Eventually driving off the butler, Daffy becomes Cubish's jester, taking uncounted pies in the face while Cubish laughs uproariously. After Cubish's death soon afterward, Daffy inherits the Cubish fortune, under the proviso that he use the money to provide honest service to the community. The now-wealthy Daffy derides the idea ("What a rube!" he says of Cubish), but his deceased benefactor returns as a ghost, making wads from Daffy's pile of money vanish until Daffy agrees to uphold the terms. The irked Daffy vows to use the money to wipe out ghosts (ala Ghostbusters) such as Cubish.

Setting himself up as a "Paranormalist at Large," Daffy persuades Bugs Bunny to appear in commercials, then hires Porky Pig (accompanied by Sylvester) as an underling; Cubish continues to make money vanish whenever Daffy seems to be operating dishonestly. Although Daffy successfully exorcises the ghosts possessing a lady duck, he discovers that Cubish has stripped his money down to his last million. He then receives a call from Porky, who is returning with Sylvester from an assignment to Dry Gulch, and Daffy reassigns him to the Superstition Mountains, much to Sylvester's chargin. Daffy then calls up Bugs, who is leaving following his encounter with Count Blood Count, and together they go up against Hugo the Abominable Snowman, with Hugo repeatedly mistaking Daffy for a rabbit.

When the city is swept with reports of a tiny elephant (from Punch Trunk), Daffy, presuming it mere hysteria, hopes to profit by soothing the public with his "expert" testimony. However, the elephant turns up on Daffy's own broadcast, making him a laughingstock. When Daffy decides to blame the debacle on the absent Porky, Cubish takes away the last of the money. Egghead appears as a singing telegram, announcing to Daffy that he is being repossesed. After the repo crew takes away his belongings, Daffy gets evicted and his building gets knocked down (with Daffy still in it).

In the epilogue, Bugs is shown enjoying his vacation in Palm Springs and reading about Daffy's downfall, and Porky and Sylvester are stranded in the Superstition Mountains, with Sylvester as cowardly as ever. After a shot of Cubish's grave, it is revealed that Daffy is back where he started, as a street corner salesman. Unfortunately, when Daffy earns a dollar bill, it instantly vanishes (this seems to imply that Cubish's curse has beckoned Daffy). The film ends with Daffy angrily shaking his fist at the sky and screaming, "Cubish!"