Nuko, Deathspire Engineer

When Nuko enters, you become the monarch.

{u}{b}{g}, {t}: Proliferate.

Whenever one or more creatures are put into a graveyard from anywhere, put a +1/+1 counter on target Demon, Insect, Horror, Skeleton, Vampire, or Zombie.

Blue, black and green nontoken creatures in your graveyard have Eternalize {3}{u}{b}.
({3}{u}{b}, Exile this card from your graveyard: Create a token that’s a copy of it, except it’s a 4/4 black Horror Zombie with no mana cost. Eternalize only as a sorcery.)