T-Rexs have been around for years. I've seen them around but usually they are where other motorcyclists are gathered.
I don't consider them "bikes" since they have a steering wheel but that's just my opinion. I don't think Can-Am Spyders are "true" bikes but they are also listed as motorcycles.
As far as I know, any state that has a helmet requirement would also require a helmet for a T-Rex although the police would probably think of it as a car if they are unfamiliar with them.