Peakjumper Daredevil

Haste, first strike
At the beginning of your upkeep, sacrifice
Peakjumper Daredevil unless you sacrifice a
Mountain you control. If you do, put a +1/+1
counter on Peakjumper Daredevil.
Stalk—Sacrifice a Mountain (At the end of each
block step, if there is an unblocked creature attacking
you, you may cast this card for its stalk cost. If you
do, choose an unblocked creature attacking you. This creature blocks that creature.)