A 78-year-old woman and her son were left with serious ankle injuries after a quad bike rider careered into them while posing with friends, a court heard.
And in the aftermath of the crash, in Manchester Road, Nelson, Gulhassan Khan fled the scene, Accrington magistrates were told.
Khan claimed he had panicked, after posing for pictures on the quad bike, when he turned the ignition key and the machine shot forward.
Mary Eastwood and her son Philip, who were walking past Khan and his friends, were seriously injured when the bike hit them and struck a wall.
Mrs Eastwood suffered a two broken ankles and her right shoulder was fractured, while Mr Eastwood endured a compound fracture of his right ankle.
Prosecutor Andrew Robinson said that although Khan left the scene, he did contact police afterwards to confess to his involvement in the incident.
Khan, 24, of Duke Street, Colne, was jailed for four months after he admitted driving without due care and attention, failing to stop after an accident, having no driving licence and having no insurance.
The prison sentence will run alongside a 33-month prison sentence he is currently serving for conspiracy to rob a bookies and convenience store.
Magistrates banned him from driving for 12 months and ordered him to take an extended driving test if he does apply for a licence on his release.
Steven Kay, defending, said: “It is right to say that he had no intention of riding the quad bike. He was simply posing for pictures and videos.”
But when he turned the ignition key, said Mr Kay, he found the bike had been left in gear and it shot forward, hitting the pedestrians.