Tommy is a resident of Valentine. Due to his burly appearance, he is viewed by the townsfolk as the local tough guy, and is well-respected in the community for his fighting prowess.
Events of Red Dead Redemption 2
While drunk, Bill Williamson starts a fight with a man in the Smithfield's Saloon and a large brawl breaks out. Tommy hears the fight from upstairs and furiously marches down.
The bartender begs him to stay out of the fight, but Tommy immediately begins to fight with Javier. Javier punches Tommy in the face, but he is unfazed by Javier's attack and begins to beat Javier to a pulp. Sensing danger, Bill then commands Arthur to save Javier from Tommy. Arthur tries to attack Tommy and initially seems to be no match for him. Tommy easily resists Arthur and throws him out the bar's front window, to then march outside and continue their brawl. After some time of continuous fighting, Arthur gains the upper hand and savagely beats Tommy, nearly killing him.
Later, Tommy can be seen eating with some men inside Smithfield's Saloon. Arthur can try to make amends, but Tommy only replies with incoherence, which seems to indicate brain damage as a result of the beating he received from Arthur.
Later Arthur can encounter a man outside who saw the fight. The man is angry at him for nearly killing Tommy and states that Tommy has "Gone funny since then", a belief shared by many townspeople in Valentine.
Arthur can encounter a man in the bar, who remembers Arthur's fight with Tommy. The man states that Tommy "ain't all there. Like the lamp's lit, but there's no one home."
Mickey states that he was once beaten up by Tommy.
In "A Quiet Time", it seems that Tommy has aphasia, a disorder resulting in impairment of language, speech, and comprehension. This would come from his fight with Arthur, who beats Tommy in the head multiple times after his defeat.
Tommy shares numerous traits and thematic elements with Russell from the Rockstar Games 2006 title Bully. Both are very feared for their immense physical strength and stature.
Both are also the first boss fist fight for the protagonists.
What the hell is going on down here?
—Tommy wondering what is going on in the saloon
Ya hit like a girl. Ya bum.
—Tommy to Javier Escuella
You want some too, huh?
—Tommy to Arthur, when Arthur attacks Tommy to save Javier