Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Mnemonic Wall

Defender
When this creature enters, you may return target instant or sorcery card from your graveyard to your hand.

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Recoil

Return target permanent to its owner's hand. Then that player discards a card.

Jarl of the Forsaken

Flash
When this creature enters, destroy target creature or planeswalker an opponent controls that was dealt damage this turn.
Foretell {1}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Swamp

Burglar Rat

When this creature enters, each opponent discards a card.

Vampire Sovereign

Flying
When this creature enters, target opponent loses 3 life and you gain 3 life.

Dinrova Horror

When this creature enters, return target permanent to its owner's hand, then that player discards a card.

Mortuary Mire

This land enters tapped.
When this land enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Ravenous Rats

When this creature enters, target opponent discards a card.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Chittering Rats

When this creature enters, target opponent puts a card from their hand on top of their library.

Okiba-Gang Shinobi

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, that player discards two cards.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Crypt Rats

{X}: This creature deals X damage to each creature and each player. Spend only black mana on X.

Lurking Deadeye

Flash
When this creature enters, destroy target creature that was dealt damage this turn.

Island

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)