Jacob Murphy is wanted in connection with an assault in Southalls Way on February 5.
The victim suffered a serious head injury, but has since been discharged from hospital.
Murphy is described as 5ft 11ins tall, of medium build, with wavy brown hair, a moustache and a beard.
The 33-year-old has links to the Norwich and Aylsham areas.
Police have advised the public not to approach Murphy if they see him.
Two people have already been charged in connection with the assault.
Storm Leake, 23, of Rouen Road, and Georgina Moore, 21, of no fixed address, were charged with GBH with intent and robbery.
They both appeared at Norwich Magistrates’ Court on February 10 and were remanded in custody to appear at Norwich Crown Court on March 10.
Anyone with information about Murphy's whereabouts is asked to contact Norfolk Constabulary on 101, quoting reference 36/8689/26.