The tendency for an object to either continue moving or remain at rest is called * gravity
inertia
momentum
friction

inertia

Explanation:

hope this helps

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.