Can someone , this is confusing me? ?

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.