Jer'hul the Necromancer

Immortal(spells and abilities cannot reduce this
creature's toughness less than 1.)
Whenever an opponent casts a spell, reveal the
top card of your library until you reveal a
creature card. Put it onto the battlefield as a
black zombie in addition to it's types. Put the remaining revealed cards into your graveyard.
{r/g}{b/g}Exile a Zombie creature you control: Shuffle target player's graveyard into their library.