The assault happened Tuesday, Sept. 5 just after 4 p.m. in the Dutch Kills section.
According to police, the 36-year-old victim was sitting on a southbound R train approaching the 36th Street Station when he asked the individual sitting next to him to stop using a vape.
An argument ensued, and the individual punched the victim in the face, police said. When the train arrived at the station, both exited.
Police said while on the platform, the individual began assaulting the victim, striking him multiple times in the head.
The individual then allegedly took $200 from the victim's pocket and fled.
The victim sustained a laceration to his head requiring stitches and was transported to NYC Health and Hospitals/ Elmhurst in stable condition.
The individual is described as a man around 25-years-old, 6'0" tall, 160 pounds, with dark complexion, a thin build, brown eyes, black hair and facial hair.
He was last seen wearing a red du-rag, a black tank top, pink shorts and blue and white sneakers.
Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477).