Necromancer's Bell

When Necromancer's Bell enters the battlefield, summon a 1/1 skeleton.
{3}, {t}: if there is a creature in your graveyard, summon a 1/1 skeleton.
{1}, {t}, sacrifice Necromancer's Bell: if you control at least 5 skeletons, search your
deck or graveyard for The Necromancer. Reveal it and put it into your hand.