A 35-year-old was attacked by two black men and a white man as he approached a taxi rank in Reading.
The victim was struck on the back of the head, causing him to fall to the floor.
The incident happened outside the taxi rank in Cemetery Junction at midnight on July, 13.
The white offender was 18 to 25-years-old with short blonde hair, skinny build, 5ft10ins tall.
The victim's mobile was also stolen during the incident.