Growth-Chamber Guardian

{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Whenever one or more +1/+1 counters are put on this creature, you may search your library for a card named Growth-Chamber Guardian, reveal it, put it into your hand, then shuffle.

Gruul Beastmaster

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever this creature attacks, another target creature you control gets +X/+0 until end of turn, where X is this creature's power.

Justiciar's Portal

Exile target creature you control, then return that card to the battlefield under its owner's control. It gains first strike until end of turn.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If this creature has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Mammoth Spider

Reach (This creature can block creatures with flying.)

Open the Gates

Search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.

Rampage of the Clans

Centaur

Destroy all artifacts and enchantments. For each permanent destroyed this way, its controller creates a 3/3 green Centaur creature token.

Rampaging Rendhorn

Riot (This creature enters with your choice of a +1/+1 counter or haste.)

Regenesis

Return up to two target permanent cards from your graveyard to your hand.

Root Snare

Prevent all combat damage that would be dealt this turn.

Sagittars' Volley

Destroy target creature with flying. Sagittars' Volley deals 1 damage to each creature with flying your opponents control.

Saruli Caretaker

Defender
{T}, Tap an untapped creature you control: Add one mana of any color.

Spirit

Knight of Sorrows

This creature can block an additional creature each combat.
Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Sauroform Hybrid

{4}{G}{G}: Adapt 4. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

Silhana Wayfinder

When this creature enters, look at the top four cards of your library. You may reveal a creature or land card from among them and put it on top of your library. Put the rest on the bottom of your library in a random order.

Ravnica Allegiance