Mouse Man made his debut as a member of the Academy of Arch-Villains
, attacking Wonder Woman
after she was blinded by the Fireworks Man
. Using his height to his advantage, along with his swiftness, he was able to prove quite a nuisance for Wonder Woman, and at one point injured Steve Trevor
during a car accident. Wonder Woman feigned surrender, and Mouse Man led the heroine back to the Academy, where she defeated and imprisoned the criminals. Mouse Man was placed in a bird cage, as his size would allow him to escape from a normal prison.
After his first defeat, Mouse Man held a grudge with Wonder Woman, and attacked her several subsequent times. During one battle, he grabbed Wonder Woman's magic lasso
and used her to entertain himself on a hamster wheel. He also accidentally shrunk Wonder Woman using his chemicals, allowing her to defeat him with a block of cheese.
Wonder Woman continued to visit Mouse Man in prison, attempting to reason with Mouse Man into reforming. He broke free from prison using his Mouselings, a group of wild mice which enabled him to escape from the cat which guarded his cage. He used his mouse motif to scare women into dropping their jewelry. He was once again able to capture Wonder Woman as his prisoner, but he was quickly defeated by the heroine with a sneeze. Mouse Man had the ability to control mice and other vermin as a side effect of his small stature.
The All-New Batman: The Brave and the Bold
Mouse Man appeared as a thief stealing data for LexCorp
with his partner, Giganta
. While Giganta battled Wonder Woman outside, Mouse Man was confronted by Batman
, who was quickly able to defeat the miniature villain. Later, a spell from Eros caused Wonder Woman and Batman to fall madly in love with each other. During their wedding ceremony, several villains who had been hired by Talia al Ghul
interrupted, and a battle ensued. Mouse Man escaped from the battle, but was caught by Catwoman
, angry at Mouse Man for his part in Batman almost marrying Wonder Woman.