Protean Hulk

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

Altar of Bone

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Angelic Arbiter

Flying
Each opponent who cast a spell this turn can't attack with creatures.
Each opponent who attacked with a creature this turn can't cast spells.

Vein Ripper

Flying
Ward—Sacrifice a creature.
Whenever a creature dies, target opponent loses 2 life and you gain 2 life.

Karador, Ghost Chieftain

This spell costs {1} less to cast for each creature card in your graveyard.
Once during each of your turns, you may cast a creature spell from your graveyard.