Lasav, Dimir Mastermind

Hexproof. (This permanent can't be the target of
spells or abilities your opponents control.)
Whenever a creature is put into an opponent's graveyard from anywhere, you may have Lasav,
Dimir Mastermind become a copy of that card
except it's name is still Lasav, Dimir Mastermind,
it's legendary in addition to its other types, and it
gains Hexproof and this ability.