Being a teacher may be a thankless job, but being a substitute may be even worse.

A student at Nimitz High School, in Houston, has gotten into a lot of trouble after he pushed a substitute teacher to the ground after she took away his cell phone during class.

The 16-year-old student -- who is reportedly six-foot-three and weights 325 pounds -- pushed the 66-year-old woman three times, with her falling to the floor on the third try. The episode was caught on camera.

The student had been caught using his phone during class and got upset when the substitute, who's a retired teacher, took it.

The student reported himself to the principal and was arrested. The teacher was treated for minor injuries.

You can see raw video of the incident below.