It was like a scene out of a movie as a reveller dressed as a caveman and holding a club went to the aid of a man being attacked in a busy town centre.
The surprising moment was captured by CCTV cameras and the footage was today released by police trying to find the assailant.
The victim, a 31-year-old man, had been drinking at a pub in Stourbridge where a fancy dress party was taking place.
As he came out of the Mitre Inn in Lower High Street, just after 1.30am, he was followed into High Street, where he was then pounced on.
The man was pushed to the ground before being kicked in the stomach and punched several times in the face. Footage of the attack shows two men in costumes, including one dressed as a caveman, running to his rescue.
The attacker is then pulled away from the injured man and walks out of view of the camera.
The victim was knocked unconscious and suffered injuries to his head and nose.
Police today released the CCTV pictures in a bid to trace his attacker.
DC John Horrobin, from the major investigation team in Dudley, said: “In the footage you will see a couple of people in fancy dress costume.
“There had been a fancy dress party at the Mitre Inn on that night and we are appealing to anyone that may have seen the victim on the night to come forward.
“The victim has little recollection of the attack and thankfully he will make a full recovery.”
The assault happened on October 27.
Anyone who can help with the investigation is urged to contact DC Horrobin by calling West Midlands Police on 101.
Alternatively people can leave information anonymously by contacting the free Crimestoppers hotline on 0800 555 111.