Marvin is a character in Banana Fish who works for Dino Golzine. On his orders he comes to be a foe to Ash and his friends.
Marvin has brown hair with black sunglasses and wears a tan shirt underneath his brown suit with a black tie.
Described as vindictive, he also has a short temper. He offers to carry out Golzine's wishes and is willing to beat people with a belt to gather information.
Marvin Crosby stands hands in pockets against a pillar outside Golzine’s manor. Smoking a cigarette and humming to himself he notices that Ash has arrived, and asks him what he is doing up so early. Hearing Ash comment on the old getting up so early referring to Golzine, he tells him to watch his mouth and he is to call him “Papa Dino”. Hearing that Ash is not here to see him, he continues to speak as he leaves asking him if he is going to make more of those videos, that he was a fan and sneers as he continues. He is cut short at being called a slur, and calls Ash a little brat at being called a white swine. Vexed, he continues to chide Ash to himself thinking if papa didn’t like him so much…
Marvin stands to the left of Gregory alone with Golzine and his cat. He hears them discuss how the gang members sent to murder their target informed them that Ash was there on the night. In response to Golzine musing that they must have talked, or handed him something Marvin grins as he questions whether he should make Ash talk.
On Golzine’s suggestion Marvin drives Ash to meet him in person. Marvin stands back against the wall outside as he waits for their meeting to be over. Turning as Ash thanks him for driving him, he is irked being dismissed as a driver no longer needed for today by calling Ash a little brat, and to just wait.
Marvin worked for him as part of Dino's criminal empire and was permitted to sexually assault Ash with Golzine doing nothing to prevent it. He followed his orders such as not making Ash talk, to listening attentively with his hands behind his back in his presence.
Someone else working for Golzine, it was Arthur who approached Marvin to establish the trap meant to lure Ash to them. In allegiance they succeed in the kidnap and luring of Ash where Marvin asserts his own authority over Arthurs.
Marvin was attracted towards Ash and later raped him when he was about 11 years old. In response to Ash's verbal jabs he generally viewed him with disdain thinking of him as a brat. Luring people in order to set a trap for Ash, he assaulted him with his belt to make him tell what he knew. He appeared prepared to follow through with matters of a sexual nature before being knocked out by Ash when he fell for it.
Skip is one of the people kidnapped by Wookie and brought to Marvin. Even though a kid, Marvin still beat him to gain answers. He bound his and Ash's hands to take them to another location before being intercepted by Shorter and Ash's gangs arrival to rescue them alongside the police. In the commotion, aiming a gun at Ash, Marvin fires hitting Skip as he ran towards him before fleeing the crime scene.