Greel, Tiefling Redeemed

Skulk, Doublestrike
When Greel enters the battlefield, draw a card,
then discard a card.
Whenever Greel attacks and isnt blocked, it deals
3 damage to the defending player.
{2}{b}{b}{r}: Untap Greel and transform it. Activate
this ability only if an opponent attacked this turn.
I am no hero, only trying my best.