Mirror Image

You may have Mirror Image enter the battlefield as a copy of a creature you control.

Reveillark

Flying
When Reveillark leaves the battlefield, return up to two target creature cards with power 2 or less from your graveyard to the battlefield.
Evoke {5}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Felidar Guardian

When Felidar Guardian enters the battlefield, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

Leechridden Swamp

({T}: Add {B}.)
Leechridden Swamp enters the battlefield tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Sefris of the Hidden Ways

Whenever one or more creature cards are put into your graveyard from anywhere, venture into the dungeon. This ability triggers only once each turn. (To venture into the dungeon, enter the first room or advance to the next room.)
Create Undead — Whenever you complete a dungeon, return target creature card from your graveyard to the battlefield.

Radiant Solar

Flying, lifelink
Whenever Radiant Solar or another nontoken creature enters the battlefield under your control, venture into the dungeon. (Enter the first room or advance to the next room.)
{W}, Discard Radiant Solar: Venture into the dungeon and you gain 3 life.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Clone

You may have Clone enter the battlefield as a copy of any creature on the battlefield.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (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 Karmic Guide enters the battlefield, return target creature card from your graveyard to the battlefield.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Phantasmal Image

You may have Phantasmal Image enter the battlefield as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Spark Double

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Ashnod's Altar

Phantom Steed

Flash
When Phantom Steed enters the battlefield, exile another target creature you control until Phantom Steed leaves the battlefield.
Whenever Phantom Steed attacks, create a tapped and attacking token that's a copy of the exiled card, except it's an Illusion in addition to its other types. Sacrifice that token at end of combat.

Peregrine Drake

Flying
When Peregrine Drake enters the battlefield, untap up to five lands.

Vesperlark

Flying
When Vesperlark leaves the battlefield, return target creature card with power 1 or less from your graveyard to the battlefield.
Evoke {1}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Liliana, Death's Majesty

+1: Create a 2/2 black Zombie creature token. Mill two cards.
−3: Return target creature card from your graveyard to the battlefield. That creature is a black Zombie in addition to its other colors and types.
−7: Destroy all non-Zombie creatures.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Panharmonicon

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

Blasting Station

{T}, Sacrifice a creature: Blasting Station deals 1 damage to any target.
Whenever a creature enters the battlefield, you may untap Blasting Station.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter the battlefield as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Emeria Shepherd

Flying
Landfall — Whenever a land enters the battlefield under your control, you may return target nonland permanent card from your graveyard to your hand. If that land is a Plains, you may return that nonland permanent card to the battlefield instead.

Parallax Wave

Fading 5 (This enchantment enters the battlefield with five fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
Remove a fade counter from Parallax Wave: Exile target creature.
When Parallax Wave leaves the battlefield, each player returns to the battlefield all cards they own exiled with Parallax Wave.

Glasspool Shore

Glasspool Shore enters the battlefield tapped.
{T}: Add {U}.

Glasspool Mimic

You may have Glasspool Mimic enter the battlefield as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.