Golgari Grave-Troll

Golgari Grave-Troll enters with a +1/+1 counter on it for each creature card in your graveyard.
{1}, Remove a +1/+1 counter from Golgari Grave-Troll: Regenerate Golgari Grave-Troll.
Dredge 6 (If you would draw a card, you may mill six cards instead. If you do, return this card from your graveyard to your hand.)

Demonfire

Demonfire deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead.
Hellbent — If you have no cards in hand, this spell can't be countered and the damage can't be prevented.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Leyline of Lifeforce

If Leyline of Lifeforce is in your opening hand, you may begin the game with it on the battlefield.
Creature spells can't be countered.

Birds of Paradise

Avatar of Discord

({B/R} can be paid with either {B} or {R}.)
Flying
When Avatar of Discord enters, sacrifice it unless you discard two cards.

Shambling Shell

Sacrifice Shambling Shell: Put a +1/+1 counter on target creature.
Dredge 3 (If you would draw a card, you may mill three cards instead. If you do, return this card from your graveyard to your hand.)

Rain of Gore

If a spell or ability would cause its controller to gain life, that player loses that much life instead.

Svogthos, the Restless Tomb

{T}: Add {C}.
{3}{B}{G}: Until end of turn, Svogthos, the Restless Tomb becomes a black and green Plant Zombie creature with "This creature's power and toughness are each equal to the number of creature cards in your graveyard." It's still a land.

Swamp

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Last Gasp

Target creature gets -3/-3 until end of turn.

Nightcreep

Until end of turn, all creatures become black and all lands become Swamps.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Forest

Vigor Mortis

Return target creature card from your graveyard to the battlefield. If {G} was spent to cast this spell, that creature enters with an additional +1/+1 counter on it.

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Giant Solifuge

({R/G} can be paid with either {R} or {G}.)
Trample; haste; shroud (This creature can't be the target of spells or abilities.)