Eliminate the Competition

As an additional cost to cast this spell, sacrifice X creatures.
Destroy X target creatures.

Ant Queen

{1}{G}: Create a 1/1 green Insect creature token.

Guul Draz Overseer

Flying
Landfall — Whenever a land you control enters, other creatures you control get +1/+0 until end of turn. If that land is a Swamp, those creatures get +2/+0 until end of turn instead.

Stone Haven Outfitter

Equipped creatures you control get +1/+1.
Whenever an equipped creature you control dies, draw a card.

Kheru Lich Lord

At the beginning of your upkeep, you may pay {2}{B}. If you do, return a creature card at random from your graveyard to the battlefield. It gains flying, trample, and haste. Exile that card at the beginning of your next end step. If it would leave the battlefield, exile it instead of putting it anywhere else.

Avatar of Discord

({B/R} can be paid with either {B} or {R}.)
Flying
When Avatar of Discord enters, sacrifice it unless you discard two cards.

Akoum Hellkite

Flying
Landfall — Whenever a land you control enters, Akoum Hellkite deals 1 damage to any target. If that land is a Mountain, Akoum Hellkite deals 2 damage instead.

Herald of Anafenza

Outlast {2}{W} ({2}{W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Whenever you activate Herald of Anafenza's outlast ability, create a 1/1 white Warrior creature token.

Heron's Grace Champion

Flash
Lifelink
When Heron's Grace Champion enters, other Humans you control get +1/+1 and gain lifelink until end of turn.

Consulate Crackdown

When Consulate Crackdown enters, exile all artifacts your opponents control until Consulate Crackdown leaves the battlefield.

Anya, Merciless Angel

Flying
Anya, Merciless Angel gets +3/+3 for each opponent whose life total is less than half their starting life total.
As long as an opponent's life total is less than half their starting life total, Anya has indestructible.

Guardian of Tazeem

Flying
Landfall — Whenever a land you control enters, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.

Sunbringer's Touch

Bolster X, where X is the number of cards in your hand. Each creature you control with a +1/+1 counter on it gains trample until end of turn. (To bolster X, choose a creature with the least toughness among creatures you control and put X +1/+1 counters on it.)

Defiant Bloodlord

Flying
Whenever you gain life, target opponent loses that much life.

Gruesome Slaughter

Until end of turn, colorless creatures you control gain "{T}: This creature deals damage equal to its power to target creature."

Orochi Hatchery

Orochi Hatchery enters with X charge counters on it.
{5}, {T}: Create a 1/1 green Snake creature token for each charge counter on Orochi Hatchery.

Dearly Departed

Flying
As long as Dearly Departed is in your graveyard, each Human creature you control enters with an additional +1/+1 counter on it.

Biomantic Mastery

Draw a card for each creature target player controls, then draw a card for each creature another target player controls.

Apocalypse Hydra

Apocalypse Hydra enters with X +1/+1 counters on it. If X is 5 or more, it enters with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from Apocalypse Hydra: It deals 1 damage to any target.

Reckless Assault

{1}, Pay 2 life: Reckless Assault deals 1 damage to any target.

Barrage Tyrant

Devoid (This card has no color.)
{2}{R}, Sacrifice another colorless creature: Barrage Tyrant deals damage equal to the sacrificed creature's power to any target.

Broodmate Dragon

Flying
When Broodmate Dragon enters, create a 4/4 red Dragon creature token with flying.

Embermaw Hellion

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
If another red source you control would deal damage to a permanent or player, it deals that much damage plus 1 to that permanent or player instead.

Blessing of Frost

Distribute X +1/+1 counters among any number of creatures you control, where X is the amount of {S} spent to cast this spell. Then draw a card for each creature you control with power 4 or greater.

Audacious Reshapers

{T}, Sacrifice an artifact: Reveal cards from the top of your library until you reveal an artifact card. Put that card onto the battlefield and the rest on the bottom of your library in a random order. Audacious Reshapers deals damage to you equal to the number of cards revealed this way.

Master of Pearls

Morph {3}{W}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Master of Pearls is turned face up, creatures you control get +2/+2 until end of turn.

Aetherstorm Roc

Flying
Whenever Aetherstorm Roc or another creature you control enters, you get {E} (an energy counter).
Whenever Aetherstorm Roc attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

Aethersquall Ancient

Flying
At the beginning of your upkeep, you get {E}{E}{E} (three energy counters).
Pay eight {E}: Return all other creatures to their owners' hands. Activate only as a sorcery.

Brood Butcher

Devoid (This card has no color.)
When Brood Butcher enters, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."
{B}{G}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.

Aethergeode Miner

Whenever Aethergeode Miner attacks, you get {E}{E} (two energy counters).
Pay {E}{E}: Exile Aethergeode Miner, then return it to the battlefield under its owner's control.

Celestial Archon

Bestow {5}{W}{W} (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 to a creature.)
Flying, first strike
Enchanted creature gets +4/+4 and has flying and first strike.

Angelic Captain

Flying
Whenever Angelic Captain attacks, it gets +1/+1 until end of turn for each other attacking Ally.

Prism Array

Converge — Prism Array enters with a crystal counter on it for each color of mana spent to cast it.
Remove a crystal counter from Prism Array: Tap target creature.
{W}{U}{B}{R}{G}: Scry 3.

Oran-Rief Hydra

Trample
Landfall — Whenever a land you control enters, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

Barroom Brawl

Target creature you control fights target creature the opponent to your left controls. Then that player may copy this spell and may choose new targets for the copy.

Ben-Ben, Akki Hermit

{T}: Ben-Ben, Akki Hermit deals damage to target attacking creature equal to the number of untapped Mountains you control.

Spawning Grounds

Enchant land
Enchanted land has "{T}: Create a 5/5 green Beast creature token with trample."

Outland Colossus

Renown 6 (When this creature deals combat damage to a player, if it isn't renowned, put six +1/+1 counters on it and it becomes renowned.)
Outland Colossus can't be blocked by more than one creature.

Ayula's Influence

Discard a land card: Create a 2/2 green Bear creature token.

Revel of the Fallen God

Create four 2/2 red and green Satyr creature tokens with haste.

Alesha, Who Smiles at Death

First strike
Whenever Alesha, Who Smiles at Death attacks, you may pay {W/B}{W/B}. If you do, return target creature card with power 2 or less from your graveyard to the battlefield tapped and attacking.

Arjun, the Shifting Flame

Flying
Whenever you cast a spell, put the cards in your hand on the bottom of your library in any order, then draw that many cards.

Munda's Vanguard

Cohort — {T}, Tap an untapped Ally you control: Put a +1/+1 counter on each creature you control.

Pristine Angel

Flying
As long as Pristine Angel is untapped, it has protection from artifacts and from each color.
Whenever you cast a spell, you may untap Pristine Angel.

Sword of Vengeance

Equipped creature gets +2/+0 and has first strike, vigilance, trample, and haste.
Equip {3}

Hixus, Prison Warden

Flash (You may cast this spell any time you could cast an instant.)
Whenever a creature deals combat damage to you, if Hixus, Prison Warden entered this turn, exile that creature until Hixus leaves the battlefield. (That creature returns under its owner's control.)

Chameleon Colossus

Changeling (This card is every creature type.)
Protection from black
{2}{G}{G}: Chameleon Colossus gets +X/+X until end of turn, where X is its power.

Dragon-Style Twins

Double strike
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Advent of the Wurm

Create a 5/5 green Wurm creature token with trample.

Arbor Colossus

Reach
{3}{G}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Arbor Colossus becomes monstrous, destroy target creature with flying an opponent controls.

Gleam of Authority

Enchant creature
Enchanted creature gets +1/+1 for each +1/+1 counter on other creatures you control.
Enchanted creature has vigilance and "{W}, {T}: Bolster 1." (To bolster 1, choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)