Mouse is both a hacker and a mercenary. She works for whatever or whomever she pleases, as long as she gets her part of the deal. However, working for Megabyte, she got double-crossed one too many times and decided to take her revenge by joining the Mainframers in their constant battles against the virus.

Mouse is a mysterious character. Her roots are unknown, and she often disappears without her trace, leaving behind her insignia, a stylized mouse. She flies a ship called, simply, Ship, and her hacking skills are unmatched. She can hack into anything, no matter how tightly it is guarded.

Mouse and Bob go way back. Their past remains shrouded in mystery, but there is a hint that they were once an item. She came to Mainframe in the middle of Season One, working for Megabyte. She ran into Bob in the process, after being double-crossed by Megabyte, and their friendship picked up again. It was when she met Dot that she ran into problems of her own. Ever since they first laid eyes on each other, they'd been jealous of each other. Jealous of what? Jealous of everything; mainly Bob's attention.

Mouse and Dot soon became good friends, however, and each supported the other in times of trouble or weakness. It seemed that their differences didn't go as far as each thought; both had passion, resolve, and a rebellious streak. Both wanted to see their city be free from harm.

Mouse is a fiery, skilled hacker with astounding fighting abilities. She will do anything to protect her allies, and strongly believes that revenge is a dish best served cold. She is a good friend to both Bob and Dot, and is extremely loyal to those she trusts.