Great Grey Wolf Sif

When Great Grey Wolf Sif enters the battlefield,
you gain life equal to the greatest toughness
among other creatures you control.

Sif is the wolf companion of
Sir Artorias, the Abysswalker.
After Artorias passed away, Sif became the guardian
of Artorias' grave in the Darkroot Garden,
to prevent others from meeting the same fate
as his former master.