Monkey Cage

When a creature enters, sacrifice this artifact and create X 2/2 green Monkey creature tokens, where X is that creature's mana value.

Jinxed Idol

At the beginning of your upkeep, this artifact deals 2 damage to you.
Sacrifice a creature: Target opponent gains control of this artifact.

Infantry Shield

Equipped creature has menace and mobilize X, where X is its power. (Whenever it attacks, create X tapped and attacking 1/1 red Warrior creature tokens. Sacrifice them at the beginning of the next end step.)
Equip {2}

Korvold, Fae-Cursed King

Flying
Whenever Korvold enters or attacks, sacrifice another permanent.
Whenever you sacrifice a permanent, put a +1/+1 counter on Korvold and draw a card.

Chitterspitter

At the beginning of your upkeep, you may sacrifice a token. If you do, put an acorn counter on this artifact.
Squirrels you control get +1/+1 for each acorn counter on this artifact.
{G}, {T}: Create a 1/1 green Squirrel creature token.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Jinxed Ring

Whenever a nontoken permanent is put into your graveyard from the battlefield, this artifact deals 1 damage to you.
Sacrifice a creature: Target opponent gains control of this artifact. (This effect lasts indefinitely.)

Minion Reflector

Whenever a nontoken creature you control enters, you may pay {2}. If you do, create a token that's a copy of that creature, except it has haste and "At the beginning of the end step, sacrifice this permanent."