Gaea's Protector

Gaea's Protector must be blocked if able.

Brambleweft Behemoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Wave-Wing Elemental

Flying
Landfall — Whenever a land you control enters, Wave-Wing Elemental gets +2/+2 until end of turn.

Fertilid

Fertilid enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Primal Plasma

As Primal Plasma enters, it becomes your choice of a 3/3 creature, a 2/2 creature with flying, or a 1/6 creature with defender.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Thunder Drake

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on Thunder Drake.

Universal Automaton

Changeling (This card is every creature type.)

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: Mothdust Changeling gains flying until end of turn.

Thicket Crasher

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other Elementals you control have trample.

Embodiment of Spring

{1}{G}, {T}, Sacrifice Embodiment of Spring: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Walker of the Grove

When Walker of the Grove leaves the battlefield, create a 4/4 green Elemental creature token.
Evoke {4}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Hydromorph Guardian

{U}, Sacrifice Hydromorph Guardian: Counter target spell that targets a creature you control.

Novellamental

Flying
Novellamental can block only creatures with flying.

Terrain Elemental

Living Totem

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
When Living Totem enters, you may put a +1/+1 counter on another target creature.

Boreal Elemental

Flying
Spells your opponents cast that target Boreal Elemental cost {2} more to cast.

Soul of the Rapids

Flying
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Aethersnipe

When Aethersnipe enters, return target nonland permanent to its owner's hand.
Evoke {1}{U}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Chillbringer

Flying
When Chillbringer enters, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.

Cloud Elemental

Flying
Cloud Elemental can block only creatures with flying.

Brackwater Elemental

When Brackwater Elemental attacks or blocks, sacrifice it at the beginning of the next end step.
Unearth {2}{U} ({2}{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.)

Healer of the Glade

When Healer of the Glade enters, you gain 3 life.

Silverglade Elemental

When Silverglade Elemental enters, you may search your library for a Forest card, put that card onto the battlefield, then shuffle.

Bloom Hulk

When Bloom Hulk enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Vaporkin

Flying
Vaporkin can block only creatures with flying.

Watercourser

{U}: Watercourser gets +1/-1 until end of turn.

Cloudkin Seer

Flying
When Cloudkin Seer enters, draw a card.

Glade Watcher

Defender
Formidable — {G}: Glade Watcher can attack this turn as though it didn't have defender. Activate only if creatures you control have total power 8 or greater.

Leafkin Druid

{T}: Add {G}. If you control four or more creatures, add {G}{G} instead.

Bloodbriar

Whenever you sacrifice another permanent, put a +1/+1 counter on Bloodbriar.

Woodland Changeling

Risen Reef

Whenever Risen Reef or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Updraft Elemental

Vorstclaw

Frost Lynx

When Frost Lynx enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Game-Trail Changeling

Changeling (This card is every creature type.)
Trample

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)