Polar Bear

Snowbound (If you control a snow-covered land
this creature gets +1/+1.)
Snowwalk (If an opponent controls a
snow-covered land, this creature is unblockable.)
Frenzy 1. (This creature gets +1/+0, if it's
unblocked.)
Maul--{g}{w/u}:{t}: Deal 3 damage to target creature
and that creature doesn't heal next cleanup step.