Tas does the best Goyf impression because he's the closest you get to a true 2 mana 4/5, which is exactly what the average Goyf is itself
I did not have that many Magic the Gathering Cards, so I used this link to a fan based collection of then available cards: The website is still up, but I have no idea if it has been updated, but I suspect even if it has not been updated you still have an enormous collection of cards that you can use to create your adventure setting
You must choose an existing creature type, such as Human or Warrior
Kozilek, Butcher of Truth's Annihilator trigger would double and force a player to sacrifice eight permanents, Kogla the Titan Ape would destroy two artifacts or enchantments, and Pathbreaker Ibex would make all your creatures absolutely massive with +2X/+2X, where X is the highest power of a creature you control
Such rare copies don't always reach that lofty height