Mighty Mouse originally had a blue costume with a red cape, like Superman; but over time this changed to a yellow costume with a red cape. As with other imitations of Superman, Mighty Mouse's super powers allow him to fly, and make him incredibly strong and invulnerable. He has demonstrated the use of "X-ray vision" in at least one cartoon, while during several cartoons he used a form of super-hypnosis that even allowed him to command inanimate objects and turn back time (as in the cartoons The Johnstown Flood and Krakatoa). Other cartoons have him leaving a red contrail as he flies which he can manipulate like a band of solid flexible matter when he so desires.
The initial formula consisted of an extended setup of a crisis which needs extraordinary help to resolve and Mighty Mouse appears to save the day.
The early, operatic Mighty Mouse cartoons often portrayed Mighty Mouse as a ruthless fighter. He would dole out a considerable amount of punishment, subduing the cats to the point of giving up their evil plan and running away. Mighty Mouse would then chase down the escaping cats, and continue beating them mercilessly, usually hurling or punching them miles away to finish the fight. A favorite move is to suddenly fly up to just under a much larger opponent's chin and throw a blinding flurry of punches that leaves the enemy reeling.
Mighty Mouse had two mouse girlfriends named Pearl Pureheart (in the cartoons) and Mitzi (in the comics during the 50s and 60s), and his arch-enemy is an evil villain cat named Oil Can Harry (who originated as a human in earlier Terrytoons as the enemy of Fanny Zilch). These characters were created for a series of Mighty Mouse cartoons that spoofed the old cliffhanger serials of the days of silent film; the cartoons usually began with Mighty Mouse and Pearl Pureheart already in a desperate situation, as if they were the next chapter of the serial. The characters often sang mock opera songs during these cartoons. Mighty Mouse was also known for singing "Here I come to save the day!" when flying into action. Mighty Mouse's home town is Mouseville, populated mostly by anthropomorphic toon mice.
Mighty Mouse fought other villains, though most only appeared in one or two cartoons. In at least two cartoons, he faced a huge, dim-witted but super-strong cat named Julius Pinhead "Schlabotka" (this cat's name was only spoken and never spelled out), whose strength rivaled Mighty Mouse's own. In another cartoon, titled The Green Line, the cats live on one side of the main street of a town and the mice on the other; a green line down the middle of the street serves as the dividing line. They agree to keep the peace as long as no one crosses it. An evil entity, a Satan cat, comes and starts the cats and mice fighting. Mighty Mouse appears and the evil spirit materializes tridents to attack him. This maneuver fails, and the devil cat disappears in a puff of smoke, like an air plane crashing to the ground. At the end, Mighty Mouse is cheered by mice and cats alike.
In the episode "Krakatoa", Mighty Mouse lassos the super-volcano Krakatoa, saving the island's inhabitants from the pyroclastic flow. Most memorably, a love-interest for Mighty Mouse makes her appearance, Krakatoa Katy. One line of her theme song is "Krakatoa Katy, she ain't no lady".
Mighty Mouse was not extraordinarily popular in theatrical cartoons, but was still Terrytoons' most popular character. What made him a cultural icon was television. Paul Terry sold the Terrytoon company to CBS television in 1955. The network began running The Mighty Mouse Playhouse in late 1955; it remained on the air for nearly twelve years (and featured The Mighty Heroes during the final season). Mighty Mouse cartoons became a staple of children's TV programming for a period of over thirty years, from the 1950s through the 1980s.
Despite the character's popularity on TV, Terrytoons produced only a handful of "Mighty Mouse" cartoons in the 1959-61 time frame; the company evidently believed that the existing library of "Mighty Mouse" episodes were enough to keep youngsters tuning-in to CBS every Saturday morning.
"The Adventures of Mighty Mouse" (renaming of Terry's Comics, where Mighty Mouse appeared)
During the 1980s, animator Ralph Bakshi (who got his start at Terrytoons) created a new series of Mighty Mouse cartoons, entitled Mighty Mouse: The New Adventures. In this series, Mighty Mouse had a real identity, Mike Mouse (Patrick Pinney voiced both identities of the character in this series), and a sidekick: Scrappy Mouse (voiced by actress Dana Hill), the little orphan. Its heavy satirical tone and humor makes it a collector's item even today; many collectors of older TV series seek out episodes of the Bakshi Mighty Mouse. The series was cancelled after two seasons, due to the controversy surrounding an episode in which Mighty Mouse sniffed a red flower he had crushed into a powder. Media watchdog Reverend Donald Wildmon asserted that he was actually snorting cocaine. CBS and Bakshi denied this assertion, and Wildmon was soon retired from his position as media watchdog.
Mighty Mouse has not been seen since Marvel Comics's 10-issue comic book series (set in the New Adventures continuity) in 1990 and 1991 except for an arcade game by Atari and a 2001 "the power of cheese" TV commercial. That commercial, set in a city not unlike New York, shows Mighty Mouse dining calmly on cheese in a restaurant while utterly unconcerned with a scene of chaos and terror visibly unfolding in the street outside. The chaos and terror come in the form of an invasion by a fleet of flying saucers. The commercial was hastily pulled off the air in the wake of the September 11, 2001 attacks.
Nickelodeon is currently working on a CGI Mighty Mouse feature film (scheduled to release some time in 2010, according to IMDB), Barry E. Jackson providing conceptual art, and screenwriting by Maurice Chauvet and Christopher Vail. A CGI TV series will follow the film. A Mighty Mouse history book is in the works and will be released to tie-in with the movie.
The rights to Mighty Mouse are now divided as a result of the 2006 corporate split of Viacom (the former owner of the Terrytoons franchise) into two separate companies. CBS Operations (a unit of the current CBS Corporation) owns the ancillary rights and trademarks to the character, while Paramount Home Entertainment/CBS DVD holds home video rights (although any sort of home video reissue has yet to be announced), and what is now CBS Television Distribution has television syndication rights (the shorts are currently out of circulation). They are also being used under license by Apple Inc's Apple Mighty Mouse.
Case Western Reserve University researchers have also bred a line of "mighty mice" that have the capability of running five to six kilometers at a speed of 20 meters per minute for up to six hours before stopping These genetically engineered mice also eat 60 percent more than normal mice, but remain fitter, trimmer and live and breed longer than normal mice in a control group. Some female mice have had offspring at 2.5 years of age, an amazing feat considering most mice do not reproduce after they are one year old. The key to this remarkable alteration in energy metabolism is the over-expression of the gene for the enzyme phospheonolpyruvate carboxykinase (PEPCK-C).