* Cards like [[http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=178016 Form of the Dragon]] do this to the player.
** Meanwhile, cards that do this to CREATURES in MagicTheGathering are too many to count. Green in particular can transform even the meekest creatures into game-ending monstrosities. However, on top of it all is [[http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=193492 Eldrazi Conscription]], which apparently can transform any creature into an EldritchAbomination.
* averted in [[Yu-Gi-Oh!]], where the card 'Elemental Hero Flame Wingman' is litterally a hero with one wing!