The man, who was in his 30s, was found outside a takeaway in Westgate, Wakefield, with serious head injuries at around 5am on August 29.
He was taken to hospital to be assessed, and West Yorkshire Police said his injuries are believed to be "life changing at this time".
Officers investigating the attack are now appealing for anyone who may have information about the incident to come forward.
Anyone who may be able to help is asked to contact West Yorkshire Police on 101, quoting incident reference number 13210438159.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.