Tommy, Casual Filth

Whenever you cast an instant or sorcery spell,
you get an experience counter. Then, if you have
five or more experience counters, exile Tommy,
Casual Filth, then return him to the battlefield
transformed under his owner's control.
Tommy, Casual Filth's power and toughness are
each equal to the total number of instant and
sorcery cards you own in exile and in your
graveyard.