Give him an ultimatum, either he stops or you break up with him. Tell him that you're not enjoying those pranks and that what's he doing is more akin to bullying than anything else. Explain to him that those kinda relationships that he sees on youtube only exist in fantasy and are unrealistic and that there's no woman who'd tolerate shit like that. If he's reluctant to stop, ask him why and what he thinks would be missing in your relationship without the pranks. If he wants you guys to be more adventurous or have more banter, then work on it in other ways.

If he refuses to see why you'd be uncomfortable with those pranks, then I don't know how to help you. If he just can't empathise with you, then there's nothing you can do. Either you continue tolerating his shitty behaviour or you break up with him and honestly he might be otherwise the nicest guy on the planet but if someone cut off my hair in my sleep, I'd break their nose. Don't let him bully you just cause you like him.