The New Adventures of Mighty Mouse and Heckle & Jeckle is a 1979–1980 television series featuring newly produced Mighty Mouse and Heckle & Jeckle cartoons. The series was produced by Filmation, and aired from 1979 to 1980 on CBS with 96 episodes (128 if counting the educational "Nature" and "Homonyms" segments, hosted by Mighty and Heckle and Jeckle respectively) produced. It was the second Mighty Mouse cartoon series, following the original Mighty Mouse Playhouse from 1955 to 1967, and followed by Mighty Mouse: The New Adventures, which aired from 1987 to 1988.

The show introduced two new characters: a vampire duck named Quacula, and Oil Can Harry's bumbling assistant, Swifty, a fat cat that can still run extremely fast. Quacula was depicted as a pale blue duck with a Daffy Duck-like bill and fangs, dressed in a blue jacket and a black cape with a red lining. He slept by day in a white coffin shaped like an egg, in the basement of a house owned by an anthropomorphic bear named Theodore. Every night Quacula would rise from his coffin and try to terrify Theodore and others, but he would never really succeed; his antics tended to be more comical than frightening. Also, Theodore would come up with one plan after another to rid himself of Quacula, but always fail to do so.

Each hour of The New Adventures of Mighty Mouse and Heckle & Jeckle consisted of two Mighty Mouse cartoons, two Heckle and Jeckle cartoons, one Quacula cartoon, and one episode of the 16-part science fiction serial The Great Space Chase. Also included was "Mighty Mouse Environmental Bulletins" and Heckle & Jeckle's "Homonyms" (to add a little educational karma). However, cartoonist Scott Shaw filed suit against Filmation due to the fact that he had created a character named Duckula for the comic book Quack! #1 (July 1976), published by Star*Reach. The matter was settled out of court, and after 16 episodes Quacula was dropped from the show. The show was shortened to a half-hour in 1980, and was moved to Sundays in its final season. In 1982, The Great Space Chase was re-edited into an 80-minute movie which had a limited release to theaters. It later appeared on home video.