Nox

(Lazav, Dimir Mastermind)
Hexproof
Whenever a creature card is put into an opponent's graveyard from anywhere, you
may have Lazav, Dimir Mastermind become
a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition
to its other types, and it has hexproof and
this ability.