Krark, The Gambler

Whenever you cast a card with the words flip, roll, or random in its text box, you may pay {u/r}. If you do, copy that spell. You may choose new targets for the copy.
Whenever you lose a flip, put a -1/-1 counter
on Krark, The Gambler.
Whenever you win a flip, put a +1/+1 counter
on Krark, The Gambler.