Better known today as Mighty Mouse, this Terrytoons produced flying rodent first appeared in the 1942 theatrical short as Super Mouse in The Mouse of Tomorrow. Basically, the mouse found a supermarket, ate super soup, super celery, and super cheese and became Super Mouse. Super Mouse buffed up, beat up some cats and freed his mouse friends all while wearing a costume that highly resembled Superman's (though a few sizes smaller). Mighty Mouse had most of the same powers as Superman including flight, strength, x-ray vision, and being bulletproof, but he also had telekinesis.
At some point during the first run of some 76 animated shorts, Super Mouse changed his name to Mighty Mouse (though not because of Superman, because of a pre-existing Super Mouse character) and changed his shirt from blue to yellow, though he kept his red cape and undies. Even though the rodent originated with heavy inspiration from the Man of Steel, Mighty Mouse went on to experience success all of his own during the 40's and 50's and even experienced revivals and new animated series in the 70's and again in the late 80's. I wonder why there was never a Bat-Mouse.