A CRAZED 'zimmer frame' thug repeatedly stabbed a man in the buttocks before slashing his face during a street brawl.
The attacker is believed to have plunged a knife into the 26-year-old's backside when an argument broke out close to the 'Four Corners' in Union Street, Glasgow.
He then slashed the young man across the face before making off towards Argyle Street at around 11.25pm yesterday.
It is understood the suspect - who was walking with a 'zimmer frame' style support frame - got into taxi with two other men.
The thug is described as a white male, aged between 20 and 25-years-old, of medium height and build.
He was wearing dark clothing with white trainers and a tammy hat.
Police said the suspect had a three-wheeled support frame, which had a shopping trolley attached.
Detective Constable Stacy Smith, from Greater Glasgow CID, said: "This was a brazen attack in Glasgow city centre which has left a man requiring hospital treatment for serious injuries.
"We are not aware of the suspect's motivation to attack the man at this time.
"Our inquiries are ongoing to determine the circumstances surrounding the attack.
"At this time, officers continue to analyse available CCTV and have been speaking with local businesses.
"I am appealing to anyone people who may have been walking or driving in the area and who could have seen the suspect, to contact police with any information that could help the inquiry by phoning 101."
The victim was rushed by ambulance to the Glasgow Royal Infirmary, where he received treatment for serious injuries.
Medical staff described his condition as "stable".