Queen of the North

Immortal (Spells and abilities cannot reduce this
creature's toughness less than 1)
When Queen of the North enters the battlefield
you become the Monarch if you control the most
snow lands.
Whenever a creature attacks you while you are
the Monarch, that creature gets -1/-0 for each
snow land you control until end of turn.
Her heart is as cold as the lands she rules.