Form of the Dragon "makes you a dragon" in the sense that your life total becomes 5 and it also deals 5 damage to a creature or player (but not planeswalker because there weren't any back then, as a card type).

But, a life total is a unique characteristic of players, not creatures, and it's not P/T, while the ability to directly damage a creature or player is distinctly different from the ability to _attack_ a player (and enter combat with a blocking creature). So no, Form of the Dragon doesn't make you into a creature.

I suppose a card that actually turned the player into a creature, now that would be a fun card and I guess it could be done without even a token to represent the creature since you have the person's own body as a physical representation. You could get vigilance to avoid having to tap, because that would be awkward. Some people might misunderstand the ability of a creature to "attack" an opponent and that might cause some trouble. Anyway, probably a card for an un-set.

/p

(for pedantry).