Master Vile (voiced by an uncredited Tom Wyner) was the father of Rita Repulsa and Rito Revolto and was based on the character Yōkai Daimaō, the ultimate antagonist in Kakuranger. He was a tall demon-like being with large ear-like appendages and wore a dark cloak that had snakes seen emerging from it and wielded a magic wand. His home planet is called Gamma Vile, which was in the M51 galaxy. His personality is that of a crotchety old man. He's a very cunning villain overall, but is very comical. He also appears to be something of a coward. Master Vile and Lord Zedd have a personal, yet obvious dislike for each other (evident when Vile found out Rita married Zedd and was very furious with her for it).
Master Vile arrived on the moon in search of the legendary Zeo Crystal during the third season of Mighty Morphin Power Rangers. He very nearly succeeded with the aid of an energy-draining monster he created and called the Blue Globber. After capturing Ninjor, the Crystal and the Rangers' Zords, Vile decided to throw an "End of the World Party" in the Angel Grove Youth Center before he would use the Zeo crystal to destroy the earth. However, Vile throwing his party gave the rangers the time and opportunity to locate and retrieve their Zords. Vile grew to giant size after Ninjor regained his energy and joined the Rangers in their battle against the Globber. Although his monster was destroyed, Vile survived the finishing attacks of both the Shogun and Ninja Megafalconzord, and still managed to retreat despite not appearing to be that badly hurt. On his retreat to the moon, he considered the failure nothing more than a minor setback and decided to stay.
Vile later summoned his old ally Dischordia (a monster that uses dance to control her victims) to battle the Rangers, and she nearly succeeded in taking control of the Rangers' minds. Vile was foiled once again, as Dischordia met her end courtesy of Ninjor and the Shogun Ultrazord.
Vile then summoned the Orb of Doom to the Earth, which he used to revert the Rangers to powerless children. He prevented Lord Zedd, Rita, Goldar, and Rito from destroying Angel Grove, revealing that he had more plans for the Earth. He sent a selection of monsters to invade the planet, led by his field general, Professor Longnose. When the invasion was thwarted by the Aquitian Rangers, Vile threw a tantrum and fled back to his home galaxy, where he claimed "the bad guy always win". Zedd was overly happy to be rid off Vile to the point he actually kissed an annoyed Goldar.
After being overthrown by the Machine Empire at the start of Power Rangers Zeo, Rita called her father and begged him to let them stay with him. Vile reluctantly agreed knowing that his daughter would be bringing "that husband of hers" and told them not to wake him when they arrive. Master Vile also stated that the Machine Empire was worse than he was.
Master Vile appeared in the Power Rangers Zeo comic book, in which the forces of the Machine Empire attacked his planet looking for Lord Zedd, who was in possession of the Ninja Power Coin energies after he and Rita destroyed them in the television series. In the end, Master Vile handed the energies over to the Machine Empire despite the Rangers' attempts to stop the Machine Empire from getting them. The Power Coin energies subplot went unresolved and has since been deemed non-canon.
Master Vile was last seen on the Cimmerian Planet, attending Dark Specter's conference. He was most likely purified (like his daughter) or destroyed by Zordon's Wave during the battles that succeeded the conference.
In the Power Rangers: Operation Overdrive episode "Once a Ranger", it is revealed that he has a grandson named Thrax.
Vile was the first villain to receive the "semi-independent villain" position - a role which would later be filled by Louie Kaboom, Prince Gasket, General Havoc, Captain Mutiny, Mandilok, and some of the monsters in S.P.D.
- The Monsters that attended Master Vile's End of the World Party at the Youth Center are Fighting Flea, Slippery Shark, Oysterizer, Robogoat, Invenusable Flytrap, Vampirus, Artistmole, Centiback, Hate Master, Miss Chief, Incisorator, See Monster, Garbage Mouth, Brick Bully's second form, and Dischordia.
- Monsters at Master Vile's conference are Crabby Cabbie, See Monster, Brick Bully's second form, Miss Chief, Lanterra, Arachnofiend, a clown dog monster, a large blue stitched monster, a furry brown tiki masked monster, and a white swirly monster.