The Underworld Cookbook

{T}, Discard a card: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{4}, {T}, Sacrifice this artifact: Return target creature card from your graveyard to your hand.

Ovalchase Daredevil

Whenever an artifact you control enters, you may return this card from your graveyard to your hand.

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

Witch's Oven

{T}, Sacrifice a creature: Create a Food token. If the sacrificed creature's toughness was 4 or greater, create two Food tokens instead. (They're artifacts with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Barren Moor

This land enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Forgotten Cave

This land enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Sabin, Master Monk

Double strike
Blitz—{2}{R}{R}, Discard a card. (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)
You may cast this card from your graveyard using its blitz ability.

Asmoranomardicadaistinaculdacar

As long as you've discarded a card this turn, you may pay {B/R} to cast this spell.
When Asmoranomardicadaistinaculdacar enters, you may search your library for a card named The Underworld Cookbook, reveal it, put it into your hand, then shuffle.
Sacrifice two Foods: Target creature deals 6 damage to itself.

Cauldron Familiar

When this creature enters, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return this card from your graveyard to the battlefield.

Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: Draw a card.)

Instant Ramen

Flash
When this artifact enters, draw a card.
{2}, {T}, Sacrifice this artifact: You gain 3 life.

Malboro

Bad Breath — When this creature enters, each opponent discards a card, loses 2 life, and exiles the top three cards of their library.
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Rapacious Guest

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Food token.
Whenever you sacrifice a Food, put a +1/+1 counter on this creature.
When this creature leaves the battlefield, target opponent loses life equal to its power.