An abuser hit a 23-year-old student so hard that he had to remove his teeth from his lungs.
Shocking images of CCTV show a hooded thug who approaches and strikes his unsuspecting victim from behind in a "totally unprovoked assault".
The abuser then searched the victim's pockets and stole his phone, wallet and money while he was unconscious on the road to Marylebone in West London.
Police, who are suing the attacker, said the victim's injuries included a skull fracture and bleeding from the brain.
A police statement said: "The assault was so horrific that the victim lost his teeth and then had to be removed from his lungs."
He was taken to the hospital and kept in a coma for weeks, police said.
The Spanish student was returning home after celebrating the end of a successful internship with friends.
But he was approached from behind by a stranger and hit with a "devastating punch" at 5:20 am on August 19th of last year.
The suspect dragged the student behind a parked car and left him lying on the road.
He then entered a nearby hotel and inadvertently attempted to order a taxi to take him away.
Detective Karl Lewis said, "It was a totally unprovoked assault on a young man who was returning home after a night out.
"The man who committed this crime is a violent thug and we can not wait to bring him to justice.
"The victim has just recovered from his physical injuries, but this attack has had a significant psychological impact.
"I urge all those who recognize the CCTV to do what is right and call the police."
No arrests have been made and the police say that the victim has now returned to Spain.
All witnesses or anyone with information are asked to call the police at 101 or via Twitter @MetCC. Quote CAD 1817 / August 19, 2018.
To provide information anonymously, contact Crimestoppers at 0800 555 111 or online at crimestoppers-uk.org.