Tireless Tribe

Discard a card: Tireless Tribe gets +0/+4 until end of turn.

Oblivion Crown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature has "Discard a card: This creature gets +1/+1 until end of turn."

Ayula's Influence

Discard a land card: Create a 2/2 green Bear creature token.

Lethal Scheme

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy target creature or planeswalker. Each creature that convoked Lethal Scheme connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Razaketh's Rite

Search your library for a card, put that card into your hand, then shuffle.
Cycling {B} ({B}, Discard this card: Draw a card.)

The Gitrog Monster

Deathtouch
At the beginning of your upkeep, sacrifice The Gitrog Monster unless you sacrifice a land.
You may play an additional land on each of your turns.
Whenever one or more land cards are put into your graveyard from anywhere, draw a card.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

Simian Brawler

Discard a land card: Simian Brawler gets +1/+1 until end of turn.

Flourishing Fox

Whenever you cycle another card, put a +1/+1 counter on Flourishing Fox.
Cycling {1} ({1}, Discard this card: Draw a card.)

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Drannith Healer

Whenever you cycle another card, you gain 1 life.
Cycling {1} ({1}, Discard this card: Draw a card.)

Fluctuator

Cycling abilities you activate cost {2} less to activate.

Collector's Vault

{2}, {T}: Draw a card, then discard a card. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Bloodthorn Flail

Equipped creature gets +2/+1.
Equip—Pay {3} or discard a card.

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Generous Ent

Reach
When Generous Ent enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Forestcycling {1} ({1}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Eagles of the North

Flying
When Eagles of the North enters, creatures you control get +1/+0 and gain first strike until end of turn.
Plainscycling {1} ({1}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Timeless Witness

When Timeless Witness enters, return target card from your graveyard to your hand.
Eternalize {5}{G}{G} ({5}{G}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Human Shaman with no mana cost. Eternalize only as a sorcery.)

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Ramunap Excavator

Memory Leak

Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it.
Cycling {1} ({1}, Discard this card: Draw a card.)

Patrol Hound

Discard a card: Patrol Hound gains first strike until end of turn.

The Necrobloom

Landfall — Whenever a land you control enters, create a 0/1 green Plant creature token. If you control seven or more lands with different names, create a 2/2 black Zombie creature token instead.
Land cards in your graveyard have dredge 2. (You may return a land card from your graveyard to your hand and mill two cards instead of drawing a card.)

Resilient Wanderer

First strike
Discard a card: Resilient Wanderer gains protection from the color of your choice until end of turn.

Noose Constrictor

Reach
Discard a card: Noose Constrictor gets +1/+1 until end of turn.

Earsplitting Rats

When Earsplitting Rats enters, each player discards a card.
Discard a card: Regenerate Earsplitting Rats.

Olivia's Dragoon

Discard a card: Olivia's Dragoon gains flying until end of turn.

Oona's Prowler

Flying
Discard a card: Oona's Prowler gets -2/-0 until end of turn. Any player may activate this ability.

Abolish

You may discard a Plains card rather than pay this spell's mana cost.
Destroy target artifact or enchantment.

Mythos of Nethroi

Destroy target nonland permanent if it's a creature or if {G}{W} was spent to cast this spell.

Cabal Initiate

Discard a card: Cabal Initiate gains lifelink until end of turn.
Threshold — Cabal Initiate gets +1/+2 as long as seven or more cards are in your graveyard.

Imposing Vantasaur

Vigilance
Cycling {1} ({1}, Discard this card: Draw a card.)

Wander in Death

Return up to two target creature cards from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

Hell Mongrel

Discard a card: Hell Mongrel gets +1/+1 until end of turn.
Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Timeless Dragon

Flying
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)
Eternalize {2}{W}{W} ({2}{W}{W}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Dragon with no mana cost. Eternalize only as a sorcery.)

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Guardian of New Benalia

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
Whenever Guardian of New Benalia enlists a creature, scry 2.
Discard a card: Guardian of New Benalia gains indestructible until end of turn. Tap it.

Murderer's Axe

Equipped creature gets +2/+2.
Equip—Discard a card.

Patchwork Gnomes

Discard a card: Regenerate Patchwork Gnomes. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)