Norwich Crown Court heard how the 12-year-old boy was nearly blinded after a pellet from Daniel Clarke's air rifle hit him in the head, missing his eye by an inch
Clarke, 22, a father-of-four, was shooting pigeons with his air rifle when he spotted the boy and his 16-year-old friend climbing a tree in Thetford, Norfolk.
Norwich Crown Court heard how the boys had a brief conversation with Clarke about what he was going to do and one of them told him he was not a pigeon
Prosecutor Christopher Youell said: "Clarke than asked him if he was sure and started firing randomly.
"He then started to walk away from the tree and told the boys, 'Wait there, I'll see if I can hit you from here'.
"Clarke told them that it would not hurt, as he had already shot his dog with the rifle.
"The younger boy then felt a sting to the right side of his head. There was a puncture wound less than an inch from the boy's eye.
"The boy climbed down from the tree and heard another .177 pellet whiz by him. He ran home and another pellet lodged in his father's car.
"When the other boy came down from the tree, Clarke continued firing at him."
The court heard how emergency services were called and a police firearms team turned up. Fortunately, the younger boy's injuries were minor.
Clarke of Thetford who had also breached two community orders admitted assault causing actual bodily harm
Judge Peter Jacobs said the prank on September 19 was an "absolutely disgraceful business" that could have left the younger boy blind.
He added: "You had been gratuitously shooting pigeons before. Then you took careful aim and shot at the younger boy, who could have been blinded.
"This was a premeditated attack involving two children with an air weapon in a public place and you continued to fire after the injury was caused."
The court heard that Clarke had a telescopic sight on his air rifle. He had previous convictions for racially aggravated assault, common assault, and threatening behaviour.
Andrew Shaw, defending, said: "It is tempting to say 'least said, soonest mended'.
"But from about 40ft away from the boys, it must be the case that there was no certainty that Clarke would hit the 12-year-old.
"To that extent, I would invite your honour to conclude that causing injury was reckless rather than intentional.
"My client's life has been blighted by drugs and alcohol. He has four children aged from seven to six months and fathered his first child aged 15.
"To say he comes from a broken society is to underestimate the situation."