Wildborn Preserver

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)
Whenever another non-Human creature you control enters, you may pay {X}. When you do, put X +1/+1 counters on this creature.

Kinnan, Bonder Prodigy

Whenever you tap a nonland permanent for mana, add one mana of any type that permanent produced.
{5}{G}{U}: Look at the top five cards of your library. You may put a non-Human creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Yeva, Nature's Herald

Flash (You may cast this spell any time you could cast an instant.)
You may cast green creature spells as though they had flash.

Elrond of the White Council

Secret council — When Elrond enters, each player secretly votes for fellowship or aid, then those votes are revealed. For each fellowship vote, the voter chooses a creature they control. You gain control of each creature chosen this way, and they gain "This creature can't attack its owner." Then for each aid vote, put a +1/+1 counter on each creature you control.

Caller of the Claw

Flash
When this creature enters, create a 2/2 green Bear creature token for each nontoken creature put into your graveyard from the battlefield this turn.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Rashmi, Eternities Crafter

Whenever you cast your first spell each turn, reveal the top card of your library. You may cast it without paying its mana cost if it's a spell with lesser mana value. If you don't cast it, put it into your hand.

Legolas, Counter of Kills

Reach
Whenever you scry, if Legolas is tapped, you may untap it. Do this only once each turn.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Legolas.

Galadriel, Gift-Giver

Whenever Galadriel enters or attacks, choose one —
• Put a +1/+1 counter on another target creature.
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Haldir, Lórien Lieutenant

Haldir enters with X +1/+1 counters on it.
Vigilance
{5}{G}: Until end of turn, other Elves you control gain vigilance and get +1/+1 for each +1/+1 counter on Haldir.

Momir Vig, Simic Visionary

Whenever you cast a green creature spell, you may search your library for a creature card, reveal it, then shuffle and put that card on top.
Whenever you cast a blue creature spell, reveal the top card of your library. If it's a creature card, put that card into your hand.

Sol Ring

Scuttling Sentinel

Flash
Vigilance
When this creature enters, put a +1/+1 counter on another target creature you control. Until end of turn, that creature becomes a blue Crab in addition to its other types and gains hexproof. (It can't be the target of spells or abilities your opponents control.)

Negate

Farhaven Elf

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

Legolas Greenleaf

Reach
Legolas can't be blocked by creatures with power 2 or less.
Whenever another legendary creature you control enters, put a +1/+1 counter on Legolas.
Whenever Legolas deals combat damage to a player, draw a card.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Arwen Undómiel

Whenever you scry, put a +1/+1 counter on target creature.
{4}{G}{U}: Scry 2.

Elven Ambush

Create a 1/1 green Elf Warrior creature token for each Elf you control.

Frilled Mystic

Flash
When this creature enters, you may counter target spell.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Elrond, Lord of Rivendell

Whenever Elrond or another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, the Ring tempts you.

Elvish Champion

Other Elf creatures get +1/+1 and have forestwalk. (They can't be blocked as long as defending player controls a Forest.)

Counterspell

Grey Havens Navigator

Arwen, Weaver of Hope

Each other creature you control enters with a number of additional +1/+1 counters on it equal to Arwen's toughness.

Ezuri, Claw of Progress

Whenever a creature you control with power 2 or less enters, you get an experience counter.
At the beginning of combat on your turn, put X +1/+1 counters on another target creature you control, where X is the number of experience counters you have.

Dwynen, Gilt-Leaf Daen

Reach (This creature can block creatures with flying.)
Other Elf creatures you control get +1/+1.
Whenever Dwynen attacks, you gain 1 life for each attacking Elf you control.