Necromancer Class

When Necromancer Class enters the battlefield,
create a 2/2 black zombie creature token.
{1}{b}{g}: Level 2
Search your library for a Zombie creature card
and put it into your graveyard. Shuffle.
{3}{b}{g}: Level 3
Whenever a Zombie creature card is milled into
your graveyard, create a tapped 2/2 black zombie creature token.