Troom, the Deserter

At the beginning of your upkeep, exile a creature
card from a player's graveyard.
For as long as that card remains exiled, you may
spend mana as if it were mana of any type to cast
that creature.
If you do, put a +2/+2 counter on that creature
and Troom, the Deserter gains protection from
a color of your choice until the end of your turn.
"The Selesnya were never too fond of my talents."