Surly General

Whenever one or more loyalty counters are
removed from a planeswalker you control, you
may remove an additional loyalty counter. If you
do, Surly General deals 2 damage to any target.
"It seems impossible, but there are a few cunning
goblins. Thing is, if you've ever taken advice from
one, you'll know how unbearable they are."
—Chandra Nalaar