Writhing Necromass

This spell costs {1} less to cast for each creature card in your graveyard.
Deathtouch

Golgari Brownscale

When this card is put into your hand from your graveyard, you gain 2 life.
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.)

Commune with the Gods

Reveal the top five cards of your library. You may put a creature or enchantment card from among them into your hand. Put the rest into your graveyard.

Scarab Feast

Exile up to three target cards from a single graveyard.
Cycling {B} ({B}, Discard this card: Draw a card.)

Mulch

Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

Basking Capybara

Descend 4 — This creature gets +3/+0 as long as there are four or more permanent cards in your graveyard.

Tapping at the Window

Look at the top three cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest into your graveyard.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tortured Existence

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

Lotleth Giant

Undergrowth — When this creature enters, it deals 1 damage to target opponent for each creature card in your graveyard.

Wight of Precinct Six

This creature gets +1/+1 for each creature card in your opponents' graveyards.

Crawling Infestation

At the beginning of your upkeep, you may mill two cards. (You may put the top two cards of your library into your graveyard.)
Whenever one or more creature cards are put into your graveyard from anywhere during your turn, create a 1/1 green Insect creature token. This ability triggers only once each turn.

Gnaw to the Bone

You gain 2 life for each creature card in your graveyard.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Crypt Incursion

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.