Owen Carling borrowed the quad from a friend in the park to take two children for a spin when tragedy struck.
The 24-year-old carried out a manoeuvre which resulted in the child’s foot slipping into the chain and cutting off his toe, Teesside Crown Court heard.
Omar Ahmad, prosecuting, said the defendant put two children on the quad bike before driving up and down the park on Waverley Terrace in Hartlepool before turning sharply to the left.
He said: “This caused the child to slip from the bike, getting his right foot caught in the chain, causing them to scream.
“The defendant stopped and took the child off the bike and when he removed the shredded shoe, the child’s big toe had been amputated and was in the shoe.”
Mr Ahmad said paramedics placed the toe in ice before the child was taken to hospital but attempts to reattach it were unsuccessful.
Carling, of Barton Avenue, Hartlepool, pleaded guilty to causing serious injury due to careless driving after the incident last year.
He was initially charged with causing serious injury due to dangerous driving, but his plea to the lesser charge relating to careless driving was accepted by the prosecution.
Michael Forrest, mitigating, said the Hartlepool man was devastated and urged the judge to show leniency towards him.
“In the circumstances of the tragic case, I would invite your honour to suspend the sentence,” he said.
“For the rest of his life he will be repaying the victim in some way or another for the injury he has caused.”
Recorder Paul Reid sentenced Carling to a two-year community order with 20 rehabilitation activity requirement days and 150 hours of unpaid work attached.
“I entirely accept the comment of the author of the pre-sentence report that you have learned a very hard lesson and have shown a great deal of remorse,” he said.
“This was an act of crass stupidity.”
Carling was also ordered to pay £500 in compensation to the child.