First Appearance: First season episode "Rock & Ride"
Modo is the largest and oldest of the Biker Mice. He stands at six-foot-nine and his mass is practically entirely muscle. But for all his strength, he is surprisingly gentle. He loves kids and treats women with a chivalrous respect. When he address Charley, he almost always adds "ma'am" to her name. Usually he remains laid back and relaxed, until riled. He is approximately twenty-eight years old at the start of Wars Are Won By Those Who Dare: Shatter Your Illusions. (This is my development; it was the only way to make ages and dates agree.)
He is also the mouse carrying the most physical scars from the Plutarkian/Martian War. He lost his right arm and possibly his eyes in the same missile blast that injured his bros Throttle and Vinnie. His replacement arm was built by Dr. Karbunkle when he was going to reprogram the Freedom Fighters to fight for Plutark. Modo's remaining right eye is probably also artificial, given the way it glows whenever the grey-furred mouse gets upset (see third season episode "Once Upon a Time on Mars Parts One - Three). The fact that he has been bionically enhanced still upsets him, even though he has come to accept how useful his mechanical arm with built-in weaponry is.
Modo is the only mouse we know to have surviving family on Mars. His nephew Rimfire joined the Freedom Fighters after the Biker Mice were captured, though the fate of his niece and Rimfire's twin Primer has not been revealed yet (see second season episode "Back to Mars Parts One - Three). Modo often refers to his mother by repeating her words of advice.
He has the most independent motorcycles of the group, probably do to the attention he pays the AI-enhanced machine. His bike is purple and designed like a Fatboy that he has named Li'l Hoss but also calls darlin' (see first season episode "A Mouse and His Motorcycle").
Wars Are Won By Those Who Dare series:
Modo finally introduced Charley to his mother, Bola, having had no chance to during her first trip to Mars.
He also told her about Stella, his first serious girlfriend. He contemplated marriage to her, but they had a bad fight before he asked. She wanted him to give up the dangerous biking stunts he, Throttle, and Vinnie had fun doing. He let his pride get away with him and decided that no girl was going to tell him what to do. Before they could patch things up, the Plutarkians began to invade Mars en masse. She got onto a refugee ship, the Olympian Fury, and he and his bros joined the Freedom Fighters. The Plutarkians destroyed the Fury and all the refugees on board. Modo was devastated and still gets choked up about her despite eight years having passed. He has made fighting in her memory his reason to keep going (read Wars Are Won By Those Who Dare: Shatter Your Illusions).
Modo recognized the self-destructive bent Throttle was spiraling into. Eight years ago, Throttle had to pull him out of a similar one when he got the news Stella was dead. But their tan-furred bro brusquely rejected any attempts he and Vinnie made to help. Not really wanting to worry Charley, he and Vinnie kept quiet about how bad it was getting. Charley figured things out on her own and took the opportunity to sort Throttle out when she had to patch him up. Modo didn't know what had happened--nor did he want to know--but whatever she told him made Throttle watch his step around her (read Wars Are Won By Those Who Dare: Put Me Back Together).
A week after Throttle and Charley's chat, Lawrence Lactavius Limburger transported them to the Olympian Fury. It was the refugee ship Stella had left Mars on and it wasn't destroyed eight years ago by the Plutarkians. Throttle's cousin Hot Rod was now its Captain. She had tagged along as part of their gang when they let her. Now she was all grown-up and married.
Modo couldn't wait to see Stella, but he couldn't get Roddie alone to ask about her. He met Sparks, the young boy Roddie was raising, at the Captain's Ball and found out about Colonel Exhaust's prejudices. He took a liking to Sparks, who was risking Roddie's wrath to keep her safe. He finally got a chance to ask Roddie about Stella and found out while she survived the Plutarkians' attack, he was still five years too late to reunite with her.
The news devastated him but not as badly as before. At least this time he had a chance to say good-bye. His good-bye was interrupted by Colonel Exhaust's coup. He kept Sparks and Axle from getting captured and he, Vinnie, and Sparks rescued Throttle, Charley, and Roddie. During the usual post-victory celebration, the new nature of Charley and Throttle's relationship came out. He was happy for them both, realizing better than Vinnie did how much they needed each other.
After everything had settled down, Tala pointed out the striking resemblance between Sparks and Modo. Sparks then explained that Stella was his mother, which made Modo his father that was left behind on Mars. Modo--hurt and angry--argued with Roddie over why she hadn't told them. She finally revealed that she was afraid of losing Sparks. They managed to work through the issues and it was agreed that Sparks would return to Earth with Modo and the others like he wanted (read Wars Are Won By Those Who Dare: Reunions).
Life with Sparks in the scoreboard has been an adjustment. Modo got Charley's help getting homeschooling supplies and gets furious at any of Limburger's goons or hired mercenaries try to use his son for bait.
Evil Jack series:
Thanks to his experience with Rimfire and Primer, Modo is the responsible mouse when Throttle isn't around and he often helps out by babysitting Hannah despite the rocky start the two of them had.