A drug user launched a "malicious and vicious" attack on his own mum while she drove him around looking for fast food, a court heard.
Lee Varney, 23, bit the victim on the arm, kicked and punched her on July 10, Derby Crown Court heard.
He also ripped off the rear-view mirror and struck her with it, it was said.
The assault left her with a black eye, and bruising to her face, head and body and required her to be treated in hospital.
In a victim impact statement, the victim said she wishes to move out of the area where she lives because she is terrified of what her son might do to her, DerbyshireLive reports.
Jailing Varney for 18 months, Judge Martyn Hurst said: “Your parents have given you nothing but support and love and you have repaid them with violence.
"In my view, this was a sadistic wanting on your part to inflict pain on your mother. A psychiatrist has assessed you and there is nothing wrong with you. You were just being malicious and vicious to your own mother.
“She was clearly vulnerable. She is, I think, 60 years of age and 5ft tall, so much smaller than you. You set out to torment her while she was driving you around Derby looking for imaginary chicken takeaways.
“Since you were a teenager you have developed some kind of antipathy to your mother causing her not to want to be home alone in the house with you because you are demanding and petulant.
“You are a young man who sits in his room smoking cannabis all day, choosing not to look for a job and hanging around with your friends drinking and smoking cannabis to a colossal extent.”
Eunice Opare-Addo, prosecuting, said on the day of the assaults Varney had been badgering his mother to take him out which she eventually did at around 10.30pm.
She said he forced her to drive around Derby looking for chicken food takeaways and while she did so he launched the attacks, the court heard.
The prosecutor said: “He told her different areas of Derby to go to and she said she did not know them so he got angry and kicked her twice as she drove down Bradshaw Way.
“She stopped outside a shop in The Morledge while he got some food and he then told her to drive to an ATM and then to another shop. As they drove back to Belper he carried on punching and kicking her and she cowered as she tried to get out of the car. He pulled her back inside and bit her twice.”
Ms Opare-Addo said as the mum drove back Varney carried on assaulting her and pulled the rearview mirror from the windscreen and hit her with it.
She said the following day the victim took herself to the hospital where she was treated. Her son, of Deepdale Road, Belper, pleaded guilty to assault occasioning actual bodily harm on his mother.
