Mush is a kind, naive Manhattan newsie. He is good friends with Racetrack and Kid Blink.
(He is shipped with Kid Blink. Blush, very popular)
All that is known is that Mush probably had hardship with money so he became a newsie.
Mush was one of a lot of newsies that were afraid to strike without support but helped when Brooklyn and the other boroughs joined. The real Mush was known to be pretty smart, as he figured out how to beat up a scabber with out getting caught by the police.
The real "Mush" Meyers earned his name because he was very romantic, or "mushy". The Mush from the movie was named because his complexion was the color of oatmeal, or "mush".