Comet, Deep Slumberer

Comet, Deep Slumberer enters the battlefield with 12 stun counters on them.
{b}{w}: Remove a stun counter choose 1 of the following:
• Exile target creature with power less than Comet
• Scry 3, then reveal the top card of your library, if it is a Dog creature draw a card
• Gain life equal to the number of dogs creatures under your control