Caltrops

Caltrops comes into play face down and can be
turned up at any time for its Activate cost.
Activate {2}
When Caltrops is turned face up, for each
attacking creature without flying flip a coin,
for each flip you win that creature deals no
combat damage this turn.
{5}: Return Caltrops to its owners hand.
"OW! OW! OW! Why would some one..."
—Lord Evishire, last words