The unfortunate teacher is 27-year-old John Webster, who starred for his college football team before becoming a teacher in the New York borough of Queens.
Webster, who is 5'10" and tips the scales at 15 and a half stone, claims he was beaten up by six-year-old Rodrigo Carpio, who is 4'2" and weighs less than four stone. The teacher was apparently left with a fractured ankle, a badly-injured knee and stress so bad that he had to visit a psychiatrist after being terrorised by the tiny tot.
"It's sort of like an angel-devil sort of thing," Webster told the New York Post.
"(Rodrigo) looks like an angel but then, all of a sudden, that halo turns into horns. It's been a nightmare. It's embarrassing. It's humiliating."
The incident allegedly took place when Webster was escorting several children to the school dining room, with the teacher claiming that Rodrigo started kicking him after being told off for his horseplay.
"I tried to hold his wrists, and he began biting me,'' Webster said. "I took him to the principal's office, and he kicked me in the ankle, and one kick landed right on my knee. I felt a pop.''
Webster has been ordered back to work against his doctor's advice, and is now suing the City of New York since repeated warnings about Rodrigo's violent streak had not been heeded.
"This kid is clearly a tiny terror," said Webster's lawyer Andrew Siben. "It's sad that teachers like Mr. Webster are not offered protection from someone who can endanger other teachers and students."
The headmaster's incident report backs up Webster's claims that he was karate kicked, while the principal was also kicked and pinched, and another teacher and a security guard were also attacked during the lad's rampage.
But Rodrigo's parents are outraged at the lawsuit - despite the boy now being on medication.
"The lawsuit is totally absurd. How could my little boy do so much damage? My poor son," Rodrigo's father Jorge told the New York Post, while his mother Josefa Marcia da Silva was equally upset.
"This is a terrible thing to say (about) a child. To every mother, their child is an angel. I know that he has problems, but he doesn't deserve to be called such names," she said, adding that his medication has helped and that he is back at school.
"He is getting help, and he is much better now."