- "Look, Butcher, we were into some bad shit, man. Even before the Mallory stuff. And that, that was... if I'm gonna make a difference, I just feel more comfortable doing it on a smaller scale. I'm a motherfucker with a heart. Whereas you? You're just a motherfucker."
- —Mother's Milk to Billy Butcher[src]
Mother’s Milk left Butcher and The Boys for a reason. Now he’s got a good job, where he’s making a difference in the lives of wayward kids, and he’s made a happy home with the love of his life, Monique. But Butcher insists he can’t fight the war on Supes without M.M.’s detail-obsessed, methodical mind. And if M.M. is being honest with himself, he misses the action. But he worries that Butcher’s win-at-all-cost pursuit of Homelander will put lives at risk – especially the people M.M. cares about.
Rekindling with The BoysEdit
Mother's Milk initially left The Boys to live a quiet life with his daughter. However, after Butcher, Frenchie and Hughie Campbell kill Translucent, M.M is persuaded into renewing his membership with the group. He is, at first, angry to find out that Butcher has also recruited Frenchie again, however soon is able to get past it as the two agree to help bring down Homelander and the rest of The Seven.
Marvin's membership with The Boys comes at a cost, however. In The Self-Preservation Society, Monique becomes angry after finding out that M.M's involvement with The Boys has put her and her daughter, Cleo, on the radar of Black Noir and Homelander. Monique and Mother's Milk argue as they are taken into protection of Susan Raynor and the CIA.
In the comicsEdit
In the comic series, Mother's Milk is an original member of the Boys and the only member to be born with Compound V in his blood. His brother also developed superpowers, expanding his bodily mass. However, he died moments after his powers manifested as his body and head continued expanding in size while he wearing a helmet, crushing his skull. Mother's Milk's father then pursued legal action action against Vought American, but died after winning one court case. After his father's death, he joined the military and became a heavyweight champion. During his championship, Mother's Milk discovered the powers afforded to him thanks to the Compound V — these included superhuman strength, agility, stamina and durability. Not long after accidentally using these powers to kill someone, he was approached by Billy and joined the Boys. His nickname, Mother's Milk, comes from his dependence on his mother's breast milk, as he is unable to survive without periodically consuming it. Mother's Milk is an expert investigator thanks to his father's teachings, and it is through this skill that he mainly assists the Boys. He also struggles to maintain a relationship with his daughter Janine, but the two are able to rekindle their relationship by the end of the comic. Unfortunately, the Boys soon discover that Butcher plans on killing every single person that has ever been exposed to Compound V, so set about to stop him. While the team is away, Butcher confronts Mother's Milk and offers him a chance to walk away. He refuses, and the two get into a fight, with Mother's Milk getting the upper hand. Butcher, however, critically injures him by detonating a grenade right next to Mother's Milk's face, and proceeds to finish him off by strangling him to death.
- "Well, this is God's work. I can't argue with that. But a man of your talents? Wasted here."
- —Billy Butcher to Mother's Milk[src]
- Skilled hand-to-hand combatant: Mother's Milk was prepared to go toe-to-toe with Frenchie, who was wielding a knife at the time and later fought him in the mall. On a phone call with Monique, he mentioned one of his duties is breaking up yard fights.
- Skilled marksman: Mother's Milk can handle a pistol.
- Skilled investigator: Mother's Milk is a skilled detective; he located A-Train's stash of Compound V after discerning that Popclaw also used the serum. Billy Butcher entrusted him to locate the source of the V being covertly run by A-Train. He used his network of contacts to help The Boys track down The Female.
- Skilled physician: Mother's Milk is a former field medic.
- Intimidation: Mother's Milk commands the respect of his inmates. He was able to quickly break up a dispute over ping pong and stopped a fight by threatening to come out of his office.
- Stealth: Mother's Milk was able to quietly infiltrate the building holding The Female.
- Bilingualism: Mother's Milk appears to be fluent in Tagalog, using the language to communicate with a salon worker while on the hunt for The Female.
- Mother's Milk's custom ringtone for Monique is Rick Astley's "Never Gonna Give You Up" and his custom ringtone for Billy Butcher is Richard Wagner's "Ride of the Valkyries."
- Mother's Milk is Episcopalian.