Aldrich, Devourer of Gods

Whenever a creature card is put into an
opponent's graveyard from anywhere, you may
pay {x}, where X is its mana value. If you do, exile
that creature card from its owner's graveyard and
Aldrich, Devourer of Gods becomes a copy of
that creature, except its name is Aldrich,
Devourer of Gods, it's legendary in addition to
its other types, and it has this ability.
Aldrich dreamt as he slowly devoured the God of the Darkmoon.