The teacher took his cell phone from him because he was using it. Using a cell phone in the classroom is not allowed by the school. He was unhappy and the animals in the classroom were having a lot of fun.
The school is Nimitz High School in the Aldine School District, near and in Houston, Texas.
• intentionally, knowingly, or recklessly cause bodily injury to another,
• intentionally or knowingly threaten another with imminent bodily injury, or
• intentionally or knowingly cause physical contact with another when he knows or should reasonably believe that the other will regard the contact as offensive or provocative.
I'm pretty sure the bully-boy knew the teacher would "reasonably" believe this contact with her to be both "offensive" and "provocative."
Aggravated assault should also be appropriate, as using or exhibiting a "deadly weapon" might Anything weighing 325 pounds can be a deadly weapon.
The teacher was taken out of the school wearing a neck brace. She doesn't want to talk about it and doesn't want to be interviewed.