Garruk the Beastmage

Whenever Carth the Lion enters the battlefield
or a planeswalker you control dies, look at the
top seven cards of your library. You may reveal
a planeswalker card from among them and put
it into your hand. Put the rest on the bottom of
your library in a random order.
Planeswalkers' loyalty abilities you activate cost
an additional [+1] to activate.