yeah. so is Firestar and Squirrel Girl.

They are just so hyped up on crack they appear to be

Technically, not.  They were mutates, because the experimental drugs that were forced into their bodies triggered the latent X-Gene in the same way that the radioactive spider bite gave Spider-Man his powers. 
 
However, their old series was called The Mutant Misadventures of Cloak & Dagger.  And they're uncharacteristically hanging around Utopia with the rest of the muties... so they're treated as mutants now.

Nope just drugs gone bad.

Oh right they got the x-gene because of the drugs . I always thought they were mutants.

If they were powered by an X-Gene then IMO they are mutants regardless of the way their powers were activated. I mean Polaris was also a latent mutant that had her powers activated by external means IIRC but she was never called a mutate. But I do agree that there are several weird things here like the one that xerox and the panel shown here. Maybe it was retconned later. I don't know.

Don't forget in the recent Cloak & Dagger one shot, it started with Tandy (uncharacteristically) sulking because they'd run several tests on her to confirm that she isn't a mutant.

Question not related to the topic at hand: If you separate them for a long enough time will Cloak be sucked into his dark dimension and dagger explode? I just want to know how necessary their symbiotic relationship is.