Mercutio, the Duelist

Haste
Whenever Mercutio attacks, you may draw a card.
If you do, discard a card.
{u}{b}{r}: Mercutio gains double strike until end of
turn. Activate this ability only once each turn.
A plague o' both your houses! They have made
worms' meat of me.
-Mercutio, 3.1