Eldritch Evolution

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card with mana value X or less, where X is 2 plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle. Exile Eldritch Evolution.

Explore

You may play an additional land this turn.
Draw a card.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Gelatinous Cube

Engulf — When Gelatinous Cube enters, exile target non-Ooze creature an opponent controls until Gelatinous Cube leaves the battlefield.
Dissolve — {X}{B}: Put target creature card with mana value X exiled with Gelatinous Cube into its owner's graveyard.

Ochre Jelly

Trample
Ochre Jelly enters with X +1/+1 counters on it.
Split — When Ochre Jelly dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters with half that many +1/+1 counters on it, rounded down.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Night's Whisper

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Forest

Unexpected Fangs

Put a +1/+1 counter and a lifelink counter on target creature.

Swamp

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Scavenging Ooze

{G}: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on Scavenging Ooze and you gain 1 life.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Predator Ooze

Indestructible
Whenever Predator Ooze attacks, put a +1/+1 counter on it.
Whenever a creature dealt damage by Predator Ooze this turn dies, put a +1/+1 counter on Predator Ooze.