In which case, as @Hussar has already posted, D&D fighters are magical. Dragonflight is magical. Giant terrestrial arthropods - which are replete in D&D, and not labelled as "magic" by the game - are magical. Etc.Magic, is anything outside of what is possible within our world.
The world of D&D isn't bound by "laws" of the sort that bind our world. (Eg in D&D, fire and earth and water and air are all elements; so D&D does not share its "chemistry" with our world.)If it's giving one, the ability to break the laws which bind the rest of the world?
So the fact that something is impossible within our world doesn't mean that it breaks the "laws" of the D&D world. That's why, in D&D, giant scorpions are not magical.