Unknown Species

Discover {3}{g}{u},{t} ({3}{g}{u},{t}: Draw a card for each creature on the battlefield that doesn't share a creature type with this creature.)
Whenever Unknown Species discover a creature type, it becomes that creature type in addition to its other types. Then put a +1/+1 counter on Unknown Species.
There are countless mysteries yet undiscovered. Other mysteries change even as you spectate them.