Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.

Impact Tremors

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

First Day of Class

Whenever a creature you control enters this turn, put a +1/+1 counter on it and it gains haste until end of turn.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Rendclaw Trow

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Swamp

Safehold Elite

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Mountain

Bloodthrone Vampire

Sacrifice a creature: This creature gets +2/+2 until end of turn.

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Hissing Iguanar

Whenever another creature dies, you may have this creature deal 1 damage to target player or planeswalker.