A man was left with a fractured eye socket after being punched and kicked in the head outside McDonald's in Briggate.
It happened outside the popular store at about 4am on Saturday, March 30.
The 30-year-old victim is having ongoing medical treatment for the injuries he sustained in the attack.
Police have now released a CCTV image of a man they want to identify.
The suspect was described as an Asian male, aged between 18 to 25.
He had dark hair, with a shaved fade to the back and sides, a chin beard and a thin moustache.
He was wearing a pale pink polo shirt with a dark trim to the collar and sleeves, blue jeans and dark shoes.
West Yorkshire Police have asked anyone who recognised him or has any information to contact 1788 Ben Maher via 101 quoting crime reference 13190164441.