Gavol, Vexing Mage

Gavol, Vexing Mage enters the battlefield with X
+1/+1 counters on it. X is equal to the number
of cards you have drawn this turn.
Whenever you draw a card, you may pay {u/r}. If
you do, put a +1/+1 counter on Gavol, and it
deals 1 damage to any target.
{u}{r}: Draw a card. Gavol deals 1 damage to you.