Marshall Mathers

{2}{w}, Marshall Mathers becomes a Rapper with First Strike and base power and toughness 4/4. His name is (what?) Slim Shady.
{4}{w}, Slim Shady becomes a Legendary Creature Rapper named Eminem with First Strike, vigilance, flying, and {x}{t}, put {x} Grammy tokens on Eminem.
(For each Grammy Token on a creature that creature gets +1/+1)