Longtusk Cub

Whenever this creature deals combat damage to a player, you get {E}{E} (two energy counters).
Pay {E}{E}: Put a +1/+1 counter on this creature.

Sage of Shaila's Claim

When this creature enters, you get {E}{E}{E} (three energy counters).

Aetherstorm Roc

Flying
Whenever this creature or another creature you control enters, you get {E} (an energy counter).
Whenever this creature attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Architect of the Untamed

Landfall — Whenever a land you control enters, you get {E} (an energy counter).
Pay eight {E}: Create a 6/6 colorless Beast artifact creature token.

Aethergeode Miner

Whenever this creature attacks, you get {E}{E} (two energy counters).
Pay {E}{E}: Exile this creature, then return it to the battlefield under its owner's control.

Highspire Infusion

Target creature gets +3/+3 until end of turn. You get {E}{E} (two energy counters).

Greenbelt Rampager

When this creature enters, pay {E}{E} (two energy counters). If you can't, return this creature to its owner's hand and you get {E}.

Attune with Aether

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You get {E}{E} (two energy counters).

Shalai, Voice of Plenty

Flying
You, planeswalkers you control, and other creatures you control have hexproof.
{4}{G}{G}: Put a +1/+1 counter on each creature you control.

Aegis of the Gods

You have hexproof. (You can't be the target of spells or abilities your opponents control.)

March of the Multitudes

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.)
Create X 1/1 white Soldier creature tokens with lifelink.