Ravenous Gigantotherium

Devour 3 (As this creature enters, you may sacrifice any number of creatures. It enters with three times that many +1/+1 counters on it.)
When this creature enters, it deals X damage divided as you choose among up to X target creatures, where X is its power. Each of those creatures deals damage equal to its power to this creature.

Lashweed Lurker

Emerge {5}{G}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, you may put target nonland permanent on top of its owner's library.

Decimator of the Provinces

Emerge {6}{G}{G}{G} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, creatures you control get +2/+2 and gain trample until end of turn.
Trample, haste

Abduction

Enchant creature
When this Aura enters, untap enchanted creature.
You control enchanted creature.
When enchanted creature dies, return that card to the battlefield under its owner's control.

Lifeline

Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.

Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Homarid Spawning Bed

{1}{U}{U}, Sacrifice a blue creature: Create X 1/1 blue Camarid creature tokens, where X is the sacrificed creature's mana value.

Life's Legacy

As an additional cost to cast this spell, sacrifice a creature.
Draw cards equal to the sacrificed creature's power.

Momentous Fall

As an additional cost to cast this spell, sacrifice a creature.
You draw cards equal to the sacrificed creature's power, then you gain life equal to its toughness.

Koma, Cosmos Serpent

This spell can't be countered.
At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil.
Sacrifice another Serpent: Choose one —
• Tap target permanent. Its activated abilities can't be activated this turn.
• Koma gains indestructible until end of turn.

Kederekt Leviathan

When this creature enters, return all other nonland permanents to their owners' hands.
Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it 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.)

Phytotitan

When this creature dies, return it to the battlefield tapped under its owner's control at the beginning of their next upkeep.

False Demise

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Lazotep Quarry

{T}: Add {C}.
{T}, Sacrifice a creature: Add one mana of any color.
{X}{2}, {T}, Sacrifice a Desert: Exile target creature card with mana value X from your graveyard. Create a token that's a copy of it, except it's a 4/4 black Zombie. Activate only as a sorcery.

Lotus Ring

Indestructible
Equipped creature gets +3/+3 and has vigilance and "{T}, Sacrifice this creature: Add three mana of any one color."
Equip {3}

Colfenor's Urn

Whenever a creature with toughness 4 or greater is put into your graveyard from the battlefield, you may exile it.
At the beginning of the end step, if three or more cards have been exiled with this artifact, sacrifice it. If you do, return those cards to the battlefield under their owner's control.

Cresting Mosasaurus

Emerge {6}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When this creature enters, if you cast it, return each non-Dinosaur creature to its owner's hand.

Garden of Freyalise

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {G}.

Disciple of Freyalise

When this creature enters, you may sacrifice another creature. If you do, you gain X life and draw X cards, where X is that creature's power.

Disciple of Freyalise // Garden of Freyalise

Fool's Demise

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.