Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Entropic Eidolon

{B}, Sacrifice Entropic Eidolon: Target player loses 1 life and you gain 1 life.
Whenever you cast a multicolored spell, you may return Entropic Eidolon from your graveyard to your hand.

Burning-Tree Emissary

When Burning-Tree Emissary enters, add {R}{G}.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Wild Cantor

({R/G} can be paid with either {R} or {G}.)
Sacrifice Wild Cantor: Add one mana of any color.

Rotten Reunion

Exile up to one target card from a graveyard. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Skirge Familiar

Rotting Rats

When Rotting Rats enters, each player discards a card.
Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Dihada's Ploy

Draw two cards, then discard a card. You gain life equal to the number of cards you've discarded this turn.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Enigma Eidolon

{U}, Sacrifice Enigma Eidolon: Target player mills three cards.
Whenever you cast a multicolored spell, you may return Enigma Eidolon from your graveyard to your hand.

Verdant Eidolon

{G}, Sacrifice Verdant Eidolon: Add three mana of any one color.
Whenever you cast a multicolored spell, you may return Verdant Eidolon from your graveyard to your hand.

Ancient Grudge

Destroy target artifact.
Flashback {G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)