A man was punched more than 20 times and bit on the hand until it "exposed flesh" in a racist attack on a bus.
Police are appealing for information after the victim, who needed stitches in his cheek after the incident, also endured "monkey noises and actions" from the suspect.
The reported attack happened on the Route 199 bus on October 2 just before 2.23am.
A spokesman for the Met Police roads and transport policing command said: "The victim was on the bus when the suspect moved to sit opposite him, the suspect began to make monkey noises and actions toward the victim and the victim has challenged him.
"The suspect responded by viciously attacked the victim punching him over 20 times and biting his hand exposing flesh, the attack left the victim requiring stitches in his cheek."
DCI Will Young said: "Roads and transport policing command treat all incidents of violence on public transport very seriously and we will do everything possible to bring offenders to justice."
Police would like to speak to the man pictured in relation to the incident.
Anyone with information should contact police on 101 or call Crimestoppers anonymously on 0800 555 111 quoting reference number 3621482/16.