Raz, Master of Forms

Whenever you cast a spell that targets a creature
you control, until your next turn, Raz becomes a
copy of the creature with the most toughness.
{3}{u/r}: Look at the top X cards of your library,
where X is equal to the highest toughness among creatures you control. Put one of them into your
hand and the rest on the bottom of your library
in any order. Activate this ability only once per
turn.