Ossification

Enchant basic land you control
When Ossification enters the battlefield, exile target creature or planeswalker an opponent controls until Ossification leaves the battlefield.

Pilgrim of the Ages

When Pilgrim of the Ages enters the battlefield, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
{6}: Return Pilgrim of the Ages from your graveyard to your hand.

Valor in Akros

Whenever a creature enters the battlefield under your control, creatures you control get +1/+1 until end of turn.

True Love's Kiss

Exile target artifact or enchantment.
Draw a card.

Infested Fleshcutter

Equipped creature gets +2/+0.
Whenever equipped creature attacks, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block." (Players dealt combat damage by it also get a poison counter.)
Equip {2}{W}

Thopter Architect

Whenever an artifact enters the battlefield under your control, target creature gains flying until end of turn.

Boon-Bringer Valkyrie

Backup 1 (When this creature enters the battlefield, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn.)
Flying, first strike, lifelink

Divine Sacrament

White creatures get +1/+1.
Threshold — White creatures get an additional +1/+1 as long as seven or more cards are in your graveyard.

Veil of Assimilation

Whenever Veil of Assimilation or another artifact enters the battlefield under your control, target creature you control gets +1/+1 and gains vigilance until end of turn.

Dragon's Presence

Dragon's Presence deals 5 damage to target attacking or blocking creature.

Fumigate

Destroy all creatures. You gain 1 life for each creature destroyed this way.

Jawbone Duelist

Double strike
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Faith's Fetters

Enchant permanent
When Faith's Fetters enters the battlefield, you gain 4 life.
Enchanted permanent can't attack or block, and its activated abilities can't be activated unless they're mana abilities.

Swooping Lookout

Plains

Mirran Bardiche

For Mirrodin! (When this Equipment enters the battlefield, create a 2/2 red Rebel creature token, then attach this to it.)
Equipped creature gets +2/+1 and has vigilance.
Equip {3}{W} ({3}{W}: Attach to target creature you control. Equip only as a sorcery.)

Arcane Signet

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

Annex Sentry

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Annex Sentry enters the battlefield, exile target artifact or creature an opponent controls with mana value 3 or less until Annex Sentry leaves the battlefield.

Progenitor Exarch

When Progenitor Exarch enters the battlefield, incubate 3 X times. (To incubate 3, create an Incubator token with three +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)
{T}: Transform target Incubator token you control.

Hexgold Hoverwings

For Mirrodin! (When this Equipment enters the battlefield, create a 2/2 red Rebel creature token, then attach this to it.)
Equipped creature has flying.
Creatures you control that are equipped get +1/+0.
Equip {2}{W}

Basilica Shepherd

Flying
When Basilica Shepherd enters the battlefield, create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Recommission

Return target artifact or creature card with mana value 3 or less from your graveyard to the battlefield. If a creature enters the battlefield this way, it enters with an additional +1/+1 counter on it.

Gold Myr

Rumor Gatherer

Alliance — Whenever another creature enters the battlefield under your control, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

Angel's Mercy

Basri's Acolyte

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Basri's Acolyte enters the battlefield, put a +1/+1 counter on each of up to two other target creatures you control.

Idyllic Grange

({T}: Add {W}.)
Idyllic Grange enters the battlefield tapped unless you control three or more other Plains.
When Idyllic Grange enters the battlefield untapped, put a +1/+1 counter on target creature you control.

Congregate

Target player gains 2 life for each creature on the battlefield.

Norn's Annex

({W/P} can be paid with either {W} or 2 life.)
Creatures can't attack you or planeswalkers you control unless their controller pays {W/P} for each of those creatures.

Celebrity Fencer

Alliance — Whenever another creature enters the battlefield under your control, put a +1/+1 counter on Celebrity Fencer.

Spirit Mantle

Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature enters the battlefield under your control, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Vedalken Orrery

You may cast spells as though they had flash.

Peace Strider

When Peace Strider enters the battlefield, you gain 3 life.

Goldwarden's Helm

For Mirrodin! (When this Equipment enters the battlefield, create a 2/2 red Rebel creature token, then attach this to it.)
Equipped creature gets +0/+1.
Equip {1}{W} ({1}{W}: Attach to target creature you control. Equip only as a sorcery.)

Rambunctious Mutt

When Rambunctious Mutt enters the battlefield, destroy target artifact or enchantment an opponent controls.

Earth-Origin Yak

When Earth-Origin Yak enters the battlefield, creatures you control get +1/+1 until end of turn.

Militia Bugler

Vigilance (Attacking doesn't cause this creature to tap.)
When Militia Bugler enters the battlefield, look at the top four cards of your library. You may reveal a creature card with power 2 or less from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Sol Ring

Swift Response

Flensing Raptor

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Flensing Raptor enters the battlefield, another target creature you control with toxic gets +1/+1 and gains flying until end of turn.

Myr Kinsmith

When Myr Kinsmith enters the battlefield, you may search your library for a Myr card, reveal it, put it into your hand, then shuffle.

Ichorplate Golem

Whenever a creature enters the battlefield under your control, if it has one or more oil counters on it, put an oil counter on it.
Creatures you control with oil counters on them get +1/+1.

Kor Halberd

Equipped creature gets +1/+1 and has vigilance.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Nurturing Presence

Enchant creature
Enchanted creature has "Whenever a creature enters the battlefield under your control, this creature gets +1/+1 until end of turn."
When Nurturing Presence enters the battlefield, create a 1/1 white Spirit creature token with flying.

Ingenious Smith

When Ingenious Smith enters the battlefield, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Whenever one or more artifacts enter the battlefield under your control, put a +1/+1 counter on Ingenious Smith. This ability triggers only once each turn.

Mesa Cavalier

Flying
When Mesa Cavalier enters the battlefield, you gain 2 life.

Mandible Justiciar

Lifelink
Whenever another artifact enters the battlefield under your control, Mandible Justiciar gets +1/+1 until end of turn.

Atraxa's Skitterfang

Atraxa's Skitterfang enters the battlefield with three oil counters on it.
At the beginning of combat on your turn, you may remove an oil counter from Atraxa's Skitterfang. When you do, target creature you control gains your choice of flying, vigilance, deathtouch, or lifelink until end of turn.

Great Desert Prospector

When Great Desert Prospector enters the battlefield, create a tapped Powerstone token for each other creature you control. (The tokens are artifacts with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Dune Mover

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Dune Mover enters the battlefield, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Gavony Silversmith

When Gavony Silversmith enters the battlefield, put a +1/+1 counter on each of up to two target creatures.

Searchlight Companion

Flying
When Searchlight Companion enters the battlefield, create a 1/1 colorless Spirit creature token.

Glistening Sphere

Glistening Sphere enters the battlefield tapped.
When Glistening Sphere enters the battlefield, proliferate.
{T}: Add one mana of any color.
Corrupted — {T}: Add three mana of any one color. Activate only if an opponent has three or more poison counters.

Skittering Surveyor

When Skittering Surveyor enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Goldnight Commander

Whenever another creature enters the battlefield under your control, creatures you control get +1/+1 until end of turn.

Mentor of the Meek

Whenever another creature with power 2 or less enters the battlefield under your control, you may pay {1}. If you do, draw a card.

Angelic Intervention

Target creature or planeswalker you control gains protection from colorless or from the color of your choice until end of turn. If it's a creature, put a +1/+1 counter on it. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything with that quality.)

Leonin Snarecaster

When Leonin Snarecaster enters the battlefield, you may tap target creature.

Goldnight Redeemer

Flying
When Goldnight Redeemer enters the battlefield, you gain 2 life for each other creature you control.

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Sunset Revelry

If an opponent has more life than you, you gain 4 life.
If an opponent controls more creatures than you, create two 1/1 white Human creature tokens.
If an opponent has more cards in hand than you, draw a card.

Prophetic Prism

When Prophetic Prism enters the battlefield, draw a card.
{1}, {T}: Add one mana of any color.

Distinguished Conjurer

Whenever another creature enters the battlefield under your control, you gain 1 life.
{4}{W}, {T}: Exile another target creature you control, then return it to the battlefield under its owner's control.

Goldvein Pick

Equipped creature gets +1/+1.
Whenever equipped creature deals combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering the battlefield don't cause abilities of permanents your opponents control to trigger.

Staff of the Sun Magus

Whenever you cast a white spell or a Plains enters the battlefield under your control, you gain 1 life.

Grateful Apparition

Flying
Whenever Grateful Apparition deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)