Rendmaw trigger 

Lignify

Enchant creature
Enchanted creature is a Treefolk with base power and toughness 0/4 and loses all abilities.

Darksteel Citadel

Caller of the Hunt

As an additional cost to cast this spell, choose a creature type.
Caller of the Hunt's power and toughness are each equal to the number of creatures of the chosen type on the battlefield.

Darkmoss Bridge

Darkmoss Bridge enters tapped.
Indestructible
{T}: Add {B} or {G}.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Junk Diver

Flying
When Junk Diver dies, return another target artifact card from your graveyard to your hand.

Demolisher Spawn

Trample, haste
Delirium — Whenever Demolisher Spawn attacks, if there are four or more card types among cards in your graveyard, other attacking creatures get +4/+4 until end of turn.

Ashnod's Altar

Grist, the Hunger Tide

As long as Grist, the Hunger Tide isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.

Deathreap Ritual

Morbid — At the beginning of each end step, if a creature died this turn, you may draw a card.

Dockside Chef

{1}{B}, Sacrifice an artifact or creature: Draw a card.

Species Specialist

As Species Specialist enters, choose a creature type.
Whenever a creature of the chosen type dies, you may draw a card.

Skittering Invasion

Create five 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this creature: Add {C}."

Bow of Nylea

Attacking creatures you control have deathtouch.
{1}{G}, {T}: Choose one —
• Put a +1/+1 counter on target creature.
• Bow of Nylea deals 2 damage to target creature with flying.
• You gain 3 life.
• Put up to four target cards from your graveyard on the bottom of your library in any order.

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Vein Ripper

Flying
Ward—Sacrifice a creature.
Whenever a creature dies, target opponent loses 2 life and you gain 2 life.

Cryptothrall

Protector — Other artifact creatures you control have hexproof.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Abstergo Entertainment

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{3}, {T}, Exile Abstergo Entertainment: Return up to one target historic card from your graveyard to your hand, then exile all graveyards. (Artifacts, legendaries, and Sagas are historic.)

Nyx Weaver

Reach
At the beginning of your upkeep, mill two cards. (Put the top two cards of your library into your graveyard.)
{1}{B}{G}, Exile Nyx Weaver: Return target card from your graveyard to your hand.

Ornithopter of Paradise

Nameless Inversion

Changeling (This card is every creature type.)
Target creature gets +3/-3 and loses all creature types until end of turn.

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Pygmy Kavu

When Pygmy Kavu enters, draw a card for each black creature your opponents control.

Haywire Mite

When Haywire Mite dies, you gain 2 life.
{G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature enchantment.

Twitching Doll

{T}: Add one mana of any color. Put a nest counter on Twitching Doll.
{T}, Sacrifice Twitching Doll: Create a 2/2 green Spider creature token with reach for each counter on Twitching Doll. Activate only as a sorcery.

Springheart Nantuko

Bestow {1}{G}
Enchanted creature gets +1/+1.
Landfall — Whenever a land you control enters, you may pay {1}{G} if Springheart Nantuko is attached to a creature you control. If you do, create a token that's a copy of that creature. If you didn't create a token this way, create a 1/1 green Insect creature token.

Noxious Gearhulk

Menace
When Noxious Gearhulk enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Blood Seeker

Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Don't Have

Trickster's Elk

Bestow {1}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3.

Gloomshrieker

Menace (This creature can't be blocked except by two or more creatures.)
When Gloomshrieker enters, return target permanent card from your graveyard to your hand.
If Gloomshrieker would die, exile it instead.

Wing Storm

Wing Storm deals damage to each player equal to twice the number of creatures that player controls with flying.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Diviner's Wand

Equipped creature has "Whenever you draw a card, this creature gets +1/+1 and gains flying until end of turn" and "{4}: Draw a card."
Whenever a Wizard creature enters, you may attach Diviner's Wand to it.
Equip {3}

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land you control enters, you gain 1 life.

Cloak and Dagger

Equipped creature gets +2/+0 and has shroud. (It can't be the target of spells or abilities.)
Whenever a Rogue creature enters, you may attach Cloak and Dagger to it.
Equip {3}

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters, destroy up to one target creature and target player mills three cards.

Biotransference

Creatures you control are artifacts in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
Whenever you cast an artifact spell, you lose 1 life and create a 2/2 black Necron Warrior artifact creature token.

Forest

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Raking Canopy

Whenever a creature with flying attacks you, Raking Canopy deals 4 damage to it.

Leaden Myr

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Valgavoth's Lair

Hexproof
Valgavoth's Lair enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Pact of the Serpent

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Ezuri's Predation

For each creature your opponents control, create a 4/4 green Phyrexian Beast creature token. Each of those tokens fights a different one of those creatures.

Crown of Doom

Whenever a creature attacks you or a planeswalker you control, it gets +2/+0 until end of turn.
{2}: Target player other than Crown of Doom's owner gains control of it. Activate only during your turn.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Dreadhound

When Dreadhound enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Swamp

Armix, Filigree Thrasher

Whenever Armix, Filigree Thrasher attacks, you may discard a card. When you do, target creature defending player controls gets -X/-X until end of turn, where X is the number of artifacts you control plus the number of artifact cards in your graveyard.
Partner (You can have two commanders if both have partner.)

Arasta of the Endless Web

Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Eyeblight's Ending

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

Reap

Return up to X target cards from your graveyard to your hand, where X is the number of black permanents target opponent controls as you cast this spell.

Palladium Myr

Essence Warden

Whenever another creature enters, you gain 1 life.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Bad Moon

Power Depot

Power Depot enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast artifact spells or activate abilities of artifacts.
Modular 1

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Tree of Tales

Warren Weirding

Target player sacrifices a creature of their choice. If a Goblin is sacrificed this way, that player creates two 1/1 black Goblin Rogue creature tokens, and those tokens gain haste until end of turn.

Tarmogoyf Nest

Enchant land
Enchanted land has "{1}{G}, {T}: Create a Tarmogoyf token." (It's a {1}{G} Lhurgoyf creature with "Tarmogoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1.")

Vault of Whispers

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters with an additional +1/+1 counter on it.

Primal Vigor

If one or more tokens would be created, twice that many of those tokens are created instead.
If one or more +1/+1 counters would be put on a creature, twice that many +1/+1 counters are put on that creature instead.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Enduring Vitality

Vigilance
Creatures you control have "{T}: Add one mana of any color."
When Enduring Vitality dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Copper Myr

Rendmaw, Creaking Nest

Menace, reach
When Rendmaw, Creaking Nest enters and whenever you play a card with two or more card types, each player creates a tapped 2/2 black Bird creature token with flying. The tokens are goaded for the rest of the game. (They attack each combat if able and attack a player other than you if able.)

Erebos, God of the Dead

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Your opponents can't gain life.
{1}{B}, Pay 2 life: Draw a card.