Apocalypse Doctor

Rats you control have deathtouch
When Apocalypse Doctor enters the battlefield
Put X 1/1 black rat creature tokens onto the battlefield, where X is your devotion to black
{t} Sacrifice Apocalypse Doctor: As long as
Apocalypse Doctor is in your graveyard, on your
turn you may play rat creatures from your
graveyard and they cost {1} less to cast