A 59-year-old man was beaten so badly that his closest family were unable to recognise him, police have said.
Detectives are appealing for the public's help in tracking down those responsible for the "breathtakingly violent and wicked" assault.
Anthony McMahon was found unconscious and barely breathing in a pool of blood in a carpark on Longwood Road, Newtownabbey, at around 10.40pm on Tuesday.
He had severe head and facial injuries, the PSNI said.
A passing police patrol spotted Mr McMahon and gave him emergency first aid until paramedics arrived at the scene.
Detective Inspector Chris Millar said the injuries sustained by Mr McMahon are such that he was left "unrecognisable to even his closest family members and will now have to undergo reconstructive surgery".
"His injuries are much more than 'serious', they are life changing.
"We are appealing for the assistance of the public in tracking down the vicious perpetrators of this brutal and sustained attack," he added.
The PSNI said Mr McMahon is well known and well liked in the local area.
Police are appealing for anyone who may have seen Mr McMahon on Tuesday to contact them. They have released CCTV images of the victim on the day he was attacked, wearing the same clothes he was found in, to help jog people's memories.
"I cannot stress enough just how breathtakingly violent and wicked this assault was," said Mr Millar.
"Please call 101, quoting reference number 1360 15/08/17 if you have any information, no matter how small or seemingly insignificant.