A group of men dubbed a "pack of hyenas" are wanted by police after a vicious, unprovoked bashing at a pub in Melbourne's north-west.

Victim Tony McDonald, 55, spent five days in hospital with injuries including a broken nose and a jaw broken in three places after he was attacked at the Union Hotel in Ascot Vale in August last year.

Tony was viciously assaulted at a pub in Melbourne last August.

Crime Stoppers has released CCTV footage showing at least five men grabbing Mr McDonald at the entrance of the hotel - surrounding him before one of them repeatedly punches him in the face. The group then followed he and his brother John outside, continuing to punch and kick him.

The Essendon resident, who suffered post-concussion, dizzy spells and headaches after the attack, can't remember what happened, but John McDonald said the group of men had been yelling abuse at passing patrons including his brother.