A man suffered a fractured skull in a hit-and-run in Doncaster.
He also suffered a fractured cheekbone and eye socket along with a bleed on the brain in the collision in Cantley in the early hours of Friday.
It is believed to have happened between 12.15am and 12.45am when the victim was cycling home from work.
Posting on Facebook, the victim's mum, Julie-Ann Bryan, urged anyone with information to contact South Yorkshire Police.
She said: "We believe the incident occurred at the junction between Everingham Road, Acacia Road and Green Boulevard but it could have been further up Green Boulevard as he doesn't remember it happening and this is the route he takes home. He doesn't even remember ringing me for help.
"He has suffered extensive injuries including fractures to his skull, cheekbone, eye socket and a bleed on the brain. He now needs major surgery.
"Any information would be much appreciated, doesn't matter how small.
"If anybody knows of any local residents' with CCTV please get in touch. Please contact me or the police as they are currently investigating the incident."
Call South Yorkshire Police on 101.