Quickling

Flash (You may cast this spell any time you could cast an instant.)
Flying
When this creature enters, sacrifice it unless you return another creature you control to its owner's hand.

Arboreal Grazer

Reach
When this creature enters, you may put a land card from your hand onto the battlefield tapped.

Wall of Blossoms

Defender
When this creature enters, draw a card.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, destroy target artifact, enchantment, or land.

Mulldrifter

Flying
When this creature 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.)

Pond Prophet

Elvish Mystic

Prosperous Innkeeper

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever another creature you control enters, you gain 1 life.

Three Tree Scribe

Whenever this creature or another creature you control leaves the battlefield without dying, put a +1/+1 counter on target creature you control.

Coiling Oracle

When this creature enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Biomass Mutation

Creatures you control have base power and toughness X/X until end of turn.

Path of Discovery

Whenever a creature you control enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Arbor Elf

Wood Elves

When this creature enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Sunshower Druid

When this creature enters, put a +1/+1 counter on target creature and you gain 1 life.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Cloud of Faeries

Flying
When this creature enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Dream Stalker

When this creature enters, return a permanent you control to its owner's hand.

Fecund Greenshell

Reach
As long as you control ten or more lands, creatures you control get +2/+2.
Whenever this creature or another creature you control with toughness greater than its power enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. Otherwise, put it into your hand.

Dreamdew Entrancer

Reach
When this creature enters, tap up to one target creature and put three stun counters on it. If you control that creature, draw two cards.

Topiary Stomper

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
This creature can't attack or block unless you control seven or more lands.

Clement, the Worrywort

Vigilance
Whenever Clement or another creature you control enters, return up to one target creature you control with lesser mana value to its owner's hand.
Frogs you control have "{T}: Add {G} or {U}. Spend this mana only to cast a creature spell."

Shrieking Drake

Flying
When this creature enters, return a creature you control to its owner's hand.

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Gala Greeters

Alliance — Whenever another creature you control enters, choose one that hasn't been chosen this turn —
• Put a +1/+1 counter on this creature.
• Create a tapped Treasure token.
• You gain 2 life.

Llanowar Elves

Barrin, Tolarian Archmage

When Barrin enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Fyndhorn Elves

Mistbreath Elder

At the beginning of your upkeep, return another creature you control to its owner's hand. If you do, put a +1/+1 counter on this creature. Otherwise, you may return this creature to its owner's hand.

Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Aggressive Biomancy

Create X tokens that are copies of target creature you control, except they have "When this token enters, it fights up to one target creature you don't control."

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Elvish Visionary

Poison Dart Frog

Reach
{T}: Add one mana of any color.
{2}: This creature gains deathtouch until end of turn.

Farhaven Elf

When this creature enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Aether Channeler

When this creature enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Faerie Impostor

Flying
When this creature enters, sacrifice it unless you return another creature you control to its owner's hand.

Valley Mightcaller

Trample
Whenever another Frog, Rabbit, Raccoon, or Squirrel you control enters, put a +1/+1 counter on this creature.