Planet of Junk is the 25th episode of The New Adventures of He-Man.
Back on Primus, He-Man and the Galactic Guardians return victorious. On the asteroid, Flogg and Slushhead literally stumble on a treasure drove of alien hi-tech gear. There's some funny stuff while Mutants try to figure out how to use it. They fail miserably, but do manage to get an image projector working -- a device that makes a person standing within its beam look like anyone he chooses and Skeletor comes up with a plan: they'll kidnap the scientists and make them repair these alien devices.
Back on Primus, Caz and Drissi are excited by the arrival of "Professor Galactica's Interstellar Circus," and decide they want to go. The scientists receive free passes to "Professor Galactica's Interstellar Circus," and decide they want to go as well. The circus turns out to be a bad joke -- with unfunny clowns and one mangy horse ridden by an overweight bareback rider. And the joke is on the scientists when "Professor Galactica" turns off the image projector and reveals himself as Skeletor and the clowns, horse and rider as Mutants. They grab the scientists, throw smoke bombs, water buckets and flocks of birds, and escape. Caz, gets in the way and is grabbed too. He-Man pursues them, but Skeletor uses the image projector to make several innocent spaceships appear to be his fleeing ships, confusing He-Man and the Galactic Guardians long enough for him to escape. He tells Flogg that he doesn't want He-Man arriving too soon and spoiling his party.
Back on the asteroid, Skeletor and the Mutants brow-beat the scientists into working on machines -- with humorous results. Gepple finds what he thinks is a weapon, aims it and it sprays popcorn. Alcon accidentally boils Slushhead's helmet water with another device. But, with enough threats, Skeletor finally gets the weapons with which to defeat He-Man. Caz seizes a moment when he is not being watched and dashes to the nearest Mutant pod and sends a warning to He-Man. But Skeletor, observing this, knew that's what the boy would do; in fact he was counting on it! Caz is re-captured.
He-Man and the Galactic Guardians arrive. The Mutants' new weapons easily defeat them, driving them off into space. He-Man manages to land his Battle Bird on the asteroid. He-Man out-fights the Mutants, but Skeletor, using the devices the scientists have repaired, defeats He-Man in a tremendous battle. Skeletor taunts the captive He-Man with his newly acquired powers, sure that the conquest of Primus is only a matter of time. Skeletor turns on a machine that will take away He-Man's superpowers-- but the scientists have booby-trapped the machine so that it makes Skeletor and the Mutants weak! He-Man easily escapes their clutches, and, while the rest of the machines self-destruct, grabs the scientists, who repair his damaged Battle Bird and leave the asteroid, with Skeletor and the Mutants, as weak as children, throwing childish tantrums. The only machine that works is the image projector, which now operates of its own volition, turning the bad guys into clowns, weird animals!