Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Swamp

Forest

Thran Vigil

Whenever one or more artifact and/or creature cards leave your graveyard during your turn, put a +1/+1 counter on target creature you control.

Blossoming Wreath

You gain life equal to the number of creature cards in your graveyard.

Spider Spawning

Create a 1/2 green Spider creature token with reach for each creature card in your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lotleth Giant

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

Liliana's Elite

Liliana's Elite gets +1/+1 for each creature card in your graveyard.

Rhizome Lurcher

Undergrowth — Rhizome Lurcher enters with a number of +1/+1 counters on it equal to the number of creature cards in your graveyard.

Molderhulk

Undergrowth — This spell costs {1} less to cast for each creature card in your graveyard.
When Molderhulk enters, return target land card from your graveyard to the battlefield.

Overwhelming Remorse

This spell costs {1} less to cast for each creature card in your graveyard.
Exile target creature or planeswalker.

Criminal Past

Commander creatures you own have menace and "This creature gets +X/+0, where X is the number of creature cards in your graveyard." (A creature with menace can't be blocked except by two or more creatures.)

Viconia, Drow Apostate

At the beginning of your upkeep, if there are four or more creature cards in your graveyard, return a creature card at random from your graveyard to your hand.
Choose a Background (You can have a Background as a second commander.)

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Genesis

At the beginning of your upkeep, if Genesis is in your graveyard, you may pay {2}{G}. If you do, return target creature card from your graveyard to your hand.

Dread Whispers

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Mosswood Dreadknight

Trample
When Mosswood Dreadknight dies, you may cast it from your graveyard as an Adventure until the end of your next turn.

Mosswood Dreadknight // Dread Whispers

Acolyte of Affliction

When Acolyte of Affliction enters, mill two cards, then you may return a permanent card from your graveyard to your hand.

Gravedigger

When Gravedigger enters, you may return target creature card from your graveyard to your hand.

Sanitarium Skeleton

{2}{B}: Return Sanitarium Skeleton from your graveyard to your hand.

Persistent Specimen

{2}{B}: Return Persistent Specimen from your graveyard to the battlefield tapped.

Gravewaker

Flying (This creature can't be blocked except by creatures with flying or reach.)
{5}{B}{B}: Return target creature card from your graveyard to the battlefield tapped.

Bortuk Bonerattle

Domain — When Bortuk Bonerattle enters, if you cast it, choose target creature card in your graveyard. Return that card to the battlefield if its mana value is less than or equal to the number of basic land types among lands you control. Otherwise, put it into your hand.

Hogaak, Arisen Necropolis

You can't spend mana to cast this spell.
Convoke, delve (Each creature you tap while casting this spell pays for {1} or one mana of that creature's color. Each card you exile from your graveyard pays for {1}.)
You may cast Hogaak, Arisen Necropolis from your graveyard.
Trample

Deathbloom Ritualist

{T}: Add X mana of any one color, where X is the number of creature cards in your graveyard.

Reclusive Taxidermist

Reclusive Taxidermist gets +3/+2 as long as there are four or more creature cards in your graveyard.
{T}: Add one mana of any color.

Spore Crawler

Shessra, Death's Whisper

Bewitching Whispers — When Shessra, Death's Whisper enters, target creature blocks this turn if able.
Whispers of the Grave — At the beginning of your end step, if a creature died this turn, you may pay 2 life. If you do, draw a card.

Sengir Connoisseur

Flying
Whenever one or more other creatures die, put a +1/+1 counter on Sengir Connoisseur. This ability triggers only once each turn.

Zombie Ogre

At the beginning of your end step, if a creature died this turn, venture into the dungeon. (Enter the first room or advance to the next room.)

Rot Shambler

Whenever another creature you control dies, put a +1/+1 counter on Rot Shambler.

Silumgar Scavenger

Flying
Exploit (When this creature enters, you may sacrifice a creature.)
Whenever another creature you control dies, put a +1/+1 counter on Silumgar Scavenger. It gains haste until end of turn if it exploited that creature.

Undercity Scrounger

{T}: Create a Treasure token. Activate only if a creature died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Torgaar, Famine Incarnate

As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed this way.
When Torgaar, Famine Incarnate enters, up to one target player's life total becomes half their starting life total, rounded down.

Kjeldoran Dead

When Kjeldoran Dead enters, sacrifice a creature.
{B}: Regenerate Kjeldoran Dead.

Rot-Tide Gargantua

Exploit (When this creature enters, you may sacrifice a creature.)
When Rot-Tide Gargantua exploits a creature, each opponent sacrifices a creature.

Grafted Wargear

Equipped creature gets +3/+2.
Whenever Grafted Wargear becomes unattached from a permanent, sacrifice that permanent.
Equip {0} ({0}: Attach to target creature you control. Equip only as a sorcery.)

Legion Vanguard

{1}, Sacrifice another creature: Legion Vanguard explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Crypt Lurker

When Crypt Lurker enters, you may sacrifice a creature or discard a creature card. If you do, draw a card.

Neverwinter Dryad

{2}, Sacrifice Neverwinter Dryad: Search your library for a basic Forest card, put it onto the battlefield tapped, then shuffle.

Tar Fiend

Devour 2 (As this enters, you may sacrifice any number of creatures. This creature enters with twice that many +1/+1 counters on it.)
When Tar Fiend enters, target player discards a card for each creature it devoured.

Indulgent Tormentor

Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature or pays 3 life.

Loathsome Curator

Exploit (When this creature enters, you may sacrifice a creature.)
Menace
When Loathsome Curator exploits a creature, destroy target creature you don't control with mana value 3 or less.

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Korozda Guildmage

{1}{B}{G}: Target creature gets +1/+1 and gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{2}{B}{G}, Sacrifice a nontoken creature: Create X 1/1 green Saproling creature tokens, where X is the sacrificed creature's toughness.

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Bone Shredder enters, destroy target nonartifact, nonblack creature.

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Fungal Infection

Target creature gets -1/-1 until end of turn. Create a 1/1 green Saproling creature token.

Yavimaya Sapherd

When Yavimaya Sapherd enters, create a 1/1 green Saproling creature token.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Jalum Tome

{2}, {T}: Draw a card, then discard a card.

Whisper of the Dross

Target creature gets -1/-1 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Atrocious Experiment

Target player mills two cards, draws two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Drown in Filth

Choose target creature. Mill four cards, then that creature gets -1/-1 until end of turn for each land card in your graveyard.

Discerning Taste

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard. You gain life equal to the greatest power among creature cards put into your graveyard this way.

Avenging Druid

Whenever Avenging Druid deals damage to an opponent, you may reveal cards from the top of your library until you reveal a land card. If you do, put that card onto the battlefield and put all other cards revealed this way into your graveyard.

Glowspore Shaman

When Glowspore Shaman enters, mill three cards. You may put a land card from your graveyard on top of your library. (To mill a card, put the top card of your library into your graveyard.)

Druidic Ritual

You may mill three cards. Then return up to one creature card and up to one land card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Slimefoot, the Stowaway

Whenever a Saproling you control dies, Slimefoot, the Stowaway deals 1 damage to each opponent and you gain 1 life.
{4}: Create a 1/1 green Saproling creature token.

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.

Satyr Wayfinder

When Satyr Wayfinder enters, reveal the top four cards of your library. You may put a land card from among them into your hand. Put the rest into your graveyard.

Summon Undead

You may mill three cards. Then return a creature card from your graveyard to the battlefield. (To mill a card, put the top card of your library into your graveyard.)

Mire Triton

Deathtouch
When Mire Triton enters, mill two cards and you gain 2 life. (To mill a card, put the top card of your library into your graveyard.)

Penumbra Bobcat

When Penumbra Bobcat dies, create a 2/1 black Cat creature token.

Fungal Plots

{1}{G}, Exile a creature card from your graveyard: Create a 1/1 green Saproling creature token.
Sacrifice two Saprolings: You gain 2 life and draw a card.

Saproling Migration

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Create two 1/1 green Saproling creature tokens. If this spell was kicked, create four of those tokens instead.

Carrier Thrall

When Carrier Thrall dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.