Craterhoof Behemoth

Haste
When Craterhoof Behemoth enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Forest

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Ashling's Prerogative

As Ashling's Prerogative enters, choose odd or even. (Zero is even.)
Each creature with mana value of the chosen quality has haste.
Each creature without mana value of the chosen quality enters tapped.

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.

Ambuscade Shaman

Whenever Ambuscade Shaman or another creature you control enters, that creature gets +2/+2 until end of turn.
Dash {3}{B} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Adaptive Automaton

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Arcane Signet

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

Berserkers' Onslaught

Attacking creatures you control have double strike.

Rage Reflection

Creatures you control have double strike.

Finale of Devastation

Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.

Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Kobold Taskmaster

Other Kobold creatures you control get +1/+0.

Rites of Initiation

Discard any number of cards at random. Creatures you control get +1/+0 until end of turn for each card discarded this way.

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Command Tower

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Boltwing Marauder

Flying
Whenever another creature you control enters, target creature gets +2/+0 until end of turn.

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Golgari Signet

In the Web of War

Whenever a creature you control enters, it gets +2/+0 and gains haste until end of turn.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Mass Hysteria

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Earthcraft

Tap an untapped creature you control: Untap target basic land.

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.)

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Grumgully, the Generous

Each other non-Human creature you control enters with an additional +1/+1 counter on it.

Kher Keep

{T}: Add {C}.
{1}{R}, {T}: Create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Sol Ring

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Mountain

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Crookshank Kobolds

Swamp

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Muraganda Petroglyphs

Crimson Kobolds

Icon of Ancestry

As Icon of Ancestry enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Kobolds of Kher Keep

God-Eternal Rhonas

Deathtouch
When God-Eternal Rhonas enters, double the power of each other creature you control until end of turn. Those creatures gain vigilance until end of turn.
When God-Eternal Rhonas dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Pathbreaker Ibex

Whenever Pathbreaker Ibex attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Gruul Signet

Kobold Overlord

First strike
Other Kobold creatures you control have first strike.

Kobold Drill Sergeant

Other Kobold creatures you control get +0/+1 and have trample.

Mana Flare

Rakdos Signet

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage instead.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Patron of the Akki

Goblin offering (You may cast this spell any time you could cast an instant by sacrificing a Goblin and paying the difference in mana costs between this and the sacrificed Goblin. Mana cost includes color.)
Whenever Patron of the Akki attacks, creatures you control get +2/+0 until end of turn.

Prossh, Skyraider of Kher

When you cast this spell, create X 0/1 red Kobold creature tokens named Kobolds of Kher Keep, where X is the amount of mana spent to cast it.
Flying
Sacrifice another creature: Prossh, Skyraider of Kher gets +1/+0 until end of turn.

Sarkhan Vol

+1: Creatures you control get +1/+1 and gain haste until end of turn.
−2: Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
−6: Create five 4/4 red Dragon creature tokens with flying.

Ashnod's Altar

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Circuitous Route

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.