Ashnod's Altar

Grenzo, Dungeon Warden

Grenzo, Dungeon Warden enters with X +1/+1 counters on it.
{2}: Put the bottom card of your library into your graveyard. If it's a creature card with power less than or equal to Grenzo's power, put it onto the battlefield.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel 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.)

Malevolent Chandelier

Flying
{2}: Put target card from a graveyard on the bottom of its owner's library. Activate only as a sorcery.

Siege-Gang Commander

When Siege-Gang Commander enters, create three 1/1 red Goblin creature tokens.
{1}{R}, Sacrifice a Goblin: Siege-Gang Commander deals 2 damage to any target.

Priest of Gix

When Priest of Gix enters, add {B}{B}{B}.

Tomb Trawler

{2}: Put target card from your graveyard on the bottom of your library.

The Cauldron of Eternity

This spell costs {2} less to cast for each creature card in your graveyard.
Whenever a creature you control dies, put it on the bottom of its owner's library.
{2}{B}, {T}, Pay 2 life: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Priest of Urabrask

When Priest of Urabrask enters, add {R}{R}{R}.

Epitaph Golem

Barkform Harvester

Changeling (This card is every creature type.)
Reach
{2}: Put target card from your graveyard on the bottom of your library.

Skirk Prospector

Junktroller

Defender
{T}: Put target card from a graveyard on the bottom of its owner's library.

Murderous Redcap

When Murderous Redcap enters, it deals damage equal to its power to any target.
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.)

Warren Soultrader

Pay 1 life, Sacrifice another creature: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Hoverstone Pilgrim

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
{2}: Put target card from a graveyard on the bottom of its owner's library.

Tel-Jilad Stylus

{T}: Put target permanent you own on the bottom of your library.

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.)

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Viscera Seer

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

Sling-Gang Lieutenant

When Sling-Gang Lieutenant enters, create two 1/1 red Goblin creature tokens.
Sacrifice a Goblin: Target player loses 1 life and you gain 1 life.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.