Subterranean Shambler

Echo {3}{R} (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 this creature enters or leaves the battlefield, it deals 1 damage to each creature without flying.

Keldon Marauders

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this creature enters or leaves the battlefield, it deals 1 damage to target player or planeswalker.

Worldgorger Dragon

Flying, trample
When Worldgorger Dragon enters, exile all other permanents you control.
When Worldgorger Dragon leaves the battlefield, return the exiled cards to the battlefield under their owners' control.

Circuit Mender

When this creature enters, you gain 2 life.
When this creature leaves the battlefield, draw a card.

Clockwork Fox

When this creature leaves the battlefield, you draw two cards and each opponent draws a card.

Spellgorger Barbarian

When this creature enters, discard a card at random.
When this creature leaves the battlefield, draw a card.

Alpine Guide

When this creature enters, you may search your library for a Mountain card, put that card onto the battlefield tapped, then shuffle.
This creature attacks each combat if able.
When this creature leaves the battlefield, sacrifice a Mountain.

Spitebellows

When this creature leaves the battlefield, it deals 6 damage to target creature.
Evoke {1}{R}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Norin, Swift Survivalist

Norin can't block.
Whenever a creature you control becomes blocked, you may exile it. You may play that card from exile this turn.

Soulgorger Orgg

Trample
When this creature enters, you lose all but 1 life.
When this creature leaves the battlefield, you gain life equal to the life you lost when it entered.