My mom says i cant get a Mohawk but i really want one so what about this?

That looks amazing, have you tried showing her that picture? I reckon if she said 'its your body I wouldn't say no', then go out and get it done anyway. If shes gets mad, remind her of what she said and tell her you must have misunderstood her or something. Or you could get a full shaven proper kind of mowhawk, she'll think its asolutely gorgeous when it starts growing out into the way it is in that photo...lol. But yeah, go for it, thats one awesome mowhawk