Wild Mongrel

Discard a card: This creature gets +1/+1 and becomes the color of your choice until end of turn.

Putrid Imp

Discard a card: This creature gains flying until end of turn.
Threshold — As long as there are seven or more cards in your graveyard, this creature gets +1/+1 and can't block.

Noose Constrictor

Reach
Discard a card: This creature gets +1/+1 until end of turn.

Dakmor Salvage

This land enters tapped.
{T}: Add {B}.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

The Gitrog Monster

Deathtouch
At the beginning of your upkeep, sacrifice The Gitrog Monster unless you sacrifice a land.
You may play an additional land on each of your turns.
Whenever one or more land cards are put into your graveyard from anywhere, draw a card.

Oblivion Crown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature has "Discard a card: This creature gets +1/+1 until end of turn."