This will be important later, but basically it prevents undying from triggering if the creature had a +1/+1 counter on it at the time of death
While not especially efficient Secure the Wastes is solid in the late game if we have a bunch of lands, letting us make a bunch of tokens on our opponent's end step and hopefully untap and kill our opponent with one attack
They'll be in a special foil, "TARDIS Showcase" form, and each is uniquely numbered 500, plus the number of the given doctor
Deathtouch Whenever this creature mutates, each opponent loses X life and you gain X life, where X is the number of times this creature has mutated
Goofy Knight For A Day represents the sheer power of the Steel ink type, bringing an unmatched physical presence to the field that can easily bully smaller characters
Notably, this means a Siege's controller can attack it