Is it normal my bf fantasizes about severely harming people?

My boyfriend is 24 and has fantasies about running people over with his car, or stomping on someone's head, or beating someone with a baseball bat or wooden plank with nails. He swore he would never actually do any of it but it scares me anyway. He's not like someone who enjoys like rough sex or spanking or any of those "pain and pleasure" things, he just wants to beat someone with something or destroy them with a car.
He makes jokes out of it most of the time and thinks it's funny or says "Yeah I know I'm a little fucked up in the head," or something like that. He gets in fights with other guys sometimes and always says he wants me to watch and wants sex immediately after these fights. He says "Guys like violence it's just how it is," but it's not even violence anymore it's breaking bones and almost killing people.
I asked him if he liked the idea of killing people and he said no, he just likes the act of "destroying," someone, not beating, "destroying." He's never harmed an animal in his life, and said he never would in a million years, he absolutely hates animal cruelty and has rescued many from abusive homes.
Sometimes when he's driving he takes my hand and puts it on his groin and looks at the people on the sidewalks or crossing the street and talks about how badly he wants to slam the gas. Sometimes he gets scary and revs the engine at crossers to get their reactions. He has an old heavy wooden bat and says if he ever does anything it would be with that one.
He tells me I'm a bit of a prude so I wouldn't get it, but I understand people have some fetishes or fantasies that are a bit odd and that's healthy, I just want to know if his is? I'm ignorant to this stuff.