Factory: Undisputed leader and mastermind of the M-Team. Excels at espionage, assassination, and looking badass. She also oversees training of new recruits.
Among the squad she is looked up to and openly admired, mostly because she's pretty awesome.
There have been many cases of missing/stolen cheesecake in the area. While Factory's well-known love of cheesecake makes her a prime suspect, to date nobody has produced solid evidence against her and she remains at large. Cheesecake owners are advised to take caution.
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Twelve: Second-in-command (sorta). A studious mouse in charge of logistics, provisioning, and weapons research. He really likes chess.
Thesis: Ballistics/trajectory specialist, also works as a spotter. Always carries a graphing calculator. He's kind of a nerd, but very friendly and extremely enthusiastic about his work. 
Fade: The squad's resident sniper and master of camouflage. Works closely with Thesis for most assignments.
Skate: An expert on guerrilla warfare, Skate knows every dirty trick in the book. Also the only one who can communicate directly to his two dead brothers.
Electric Cucumber: Sounding like a really bad Megaman boss, Electric Cucumber was a "fine" mouse, apparently. Nowadays he's pretty dead. He sees his brother's safety as his duty and has managed to get him out of some pretty dire situations. 
Squid: Skate's other brother. Quieter than Cucumber, he acts as a scout for Skate and is extremely good at gathering intel.
House: A cook.