When a strange planetoid appears near the moon, two astronauts are sent to investigate. They discover an ancient space dumpster, and mistakenly open it, freeing the Evil Space Aliens trapped within for the past 10,000 years. Intergalactic sorceress Rita Repulsa and her goons (Goldar, a golden armored Ape/Griffin; Baboo, a blue-furred flying monkey; Squatt, Baboo's stout impish pal; and Finster, a white dog-like inventive creature) set their sights on the nearby planet, Earth. Luckily, the mystical sage behind Rita's original imprisonment, Zordon of Eltar, has remained there (trapped in a Time Warp, limiting him to appearing as just a transmission of his head inside of a large plasma tube), awaiting her eventual escape. At his Command Center building, he has his robotic assistant, Alpha 5, seek out a group of five brave teenagers with attitudes to combat the aliens. Alpha plucks five friends from a Juice Bar in the town of Angel Grove, California. They're reluctantly given Power Morphers, which enable them to transform their bodies into magical suits empowered by the spirits of dinosaurs. After facing Rita's foot-soldiers, the Putty Patrollers, the five teens are convinced of the danger, and agree to become the Mighty Morphin Power Rangers: Jason, the Red Tyrannosaurus Ranger; Zack, the Black Mastodon Ranger; Billy, the Blue Triceratops Ranger; Trini, the Yellow Sabertooth Tiger Ranger; and Kimberly, the Pink Pterodactyl Ranger. Together, they can call forth massive fighting machines based on their respective dinos, and combine those into a single huge humanoid robot Megazord. They use their morphing powers to fend off Goldar, who attacks Angel Grove and with Rita's magic, soon grows gigantically. After the successful battle using their powerful Megazord, the five teens agree to help Zordon & Alpha 5 defend the Earth for as long as it takes.