Bat-Mite appears as a small humanoid wearing a costume similar to that worn by the hero Batman. Bat-Mite claims to be Batman's biggest fan and travels to our dimension to watch his hero in action. At times when Batman and Robin appear to be having too easy a time of it, Bat-Mite will use his magic powers to make the situation more challenging for his hero.

Bat-Mite and his Superman counterpart, Mr. Mxyzptlk, appeared in one comic in which Mxyzpltlk pursued Bat-Mite through a number of times and dimesions in the DC Universe, laying waste to heroes and worlds alike.