Knowledge Seeker

Vigilance
Whenever you draw your second card each turn, put a +1/+1 counter on this creature.
When this creature dies, create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Aang and Katara

Whenever Aang and Katara enter or attack, create X 1/1 white Ally creature tokens, where X is the number of tapped artifacts and/or creatures you control.

Platypus-Bear

Defender
When this creature enters, mill two cards. (Put the top two cards of your library into your graveyard.)
As long as there is a Lesson card in your graveyard, this creature can attack as though it didn't have defender.

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Forest

Cat-Owl

Flying
Whenever this creature attacks, untap target artifact or creature.

Creeping Crystal Coating

Flash
Enchant creature
Enchanted creature gets +0/+3 and has "Whenever this creature attacks, create a Food token." (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Earth Kingdom Protectors

Vigilance
Sacrifice this creature: Another target Ally you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Plains

Dutiful Knowledge Seeker

Whenever one or more cards are put into a library from anywhere, put a +1/+1 counter on this creature.
{3}: Put target card from a graveyard on the bottom of its owner's library.

Aang's Defense

Target blocking creature you control gets +2/+2 until end of turn.
Draw a card.

Koma's Coil

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on this enchantment.
As long as this enchantment has seven or more quest counters on it, creatures you control get +5/+5.

The Blue Spirit

You may cast the first creature spell you cast each turn as though it had flash.
Whenever a nontoken creature you control enters during combat, draw a card.

Earth Kingdom General

When this creature enters, earthbend 2. (Target land you control becomes a 0/0 creature with haste that's still a land. Put two +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)
Whenever you put one or more +1/+1 counters on a creature, you may gain that much life. Do this only once each turn.

Badgermole

When this creature enters, earthbend 2. (Target land you control becomes a 0/0 creature with haste that's still a land. Put two +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)
Creatures you control with +1/+1 counters on them have trample.

Hermitic Herbalist

{T}: Add one mana of any color.
{T}: Add two mana in any combination of colors. Spend this mana only to cast Lesson spells.

Flexible Waterbender

Vigilance
Waterbend {3}: This creature has base power and toughness 5/2 until end of turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Earth King's Lieutenant

Trample
When this creature enters, put a +1/+1 counter on each other Ally creature you control.
Whenever another Ally you control enters, put a +1/+1 counter on this creature.

Treetop Village

This land enters tapped.
{T}: Add {G}.
{1}{G}: This land becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Bear

Momo, Playful Pet

Flying, vigilance
When Momo leaves the battlefield, choose one —
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
• Put a +1/+1 counter on target creature you control.
• Scry 2.

Empty City Ruse

Target opponent skips all combat phases of their next turn.

Avatar Kuruk

Whenever you cast a spell, create a 1/1 colorless Spirit creature token with "This token can't block or be blocked by non-Spirit creatures."
Exhaust — Waterbend {20}: Take an extra turn after this one. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}. Activate each exhaust ability only once.)

The Legend of Kuruk

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Scry 2, then draw a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Kuruk // Avatar Kuruk

Momo, Friendly Flier

Flying
The first non-Lemur creature spell with flying you cast during each of your turns costs {1} less to cast.
Whenever another creature you control with flying enters, Momo gets +1/+1 until end of turn.

Boomerang Basics

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Aardvark Sloth

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Foggy Swamp Vinebender

This creature can't be blocked by creatures with power 2 or less.
Waterbend {5}: Put a +1/+1 counter on this creature. Activate only during your turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Dark Depths

Dark Depths enters with ten ice counters on it.
{3}: Remove an ice counter from Dark Depths.
When Dark Depths has no ice counters on it, sacrifice it. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Katara, the Fearless

If a triggered ability of an Ally you control triggers, that ability triggers an additional time.

Momo, Rambunctious Rascal

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Momo enters, he deals 4 damage to target tapped creature an opponent controls.

Captain Sisay

{T}: Search your library for a legendary card, reveal that card, put it into your hand, then shuffle.

Bison Whistle

{1}, {T}: Look at the top card of your library. If it's a Bison card, you may put it onto the battlefield. If it's a creature card, you may reveal it and put it into your hand. Otherwise, you may put it into your graveyard.

Ty Lee, Chi Blocker

Flash
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Ty Lee enters, tap up to one target creature. It doesn't untap during its controller's untap step for as long as you control Ty Lee.

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Earth Kingdom Jailer

When this creature enters, exile up to one target artifact, creature, or enchantment an opponent controls with mana value 3 or greater until this creature leaves the battlefield.

Otter-Penguin

Whenever you draw your second card each turn, this creature gets +1/+2 until end of turn and can't be blocked this turn.

Koma, Cosmos Serpent

This spell can't be countered.
At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil.
Sacrifice another Serpent: Choose one —
• Tap target permanent. Its activated abilities can't be activated this turn.
• Koma gains indestructible until end of turn.

Sokka, Swordmaster

Vigilance
Equipment spells you cast cost {1} less to cast for each Ally you control.
At the beginning of combat on your turn, attach up to one target Equipment you control to Sokka.

Lita, Mechanical Engineer

Vigilance
At the beginning of your end step, untap each other artifact creature you control.
{3}{W}, {T}: Create a 5/5 colorless Vehicle artifact token named Zeppelin with flying and crew 3. (It has "Tap any number of creatures you control with total power 3 or more: This token becomes an artifact creature until end of turn.")

Hakoda, Selfless Commander

Vigilance
You may look at the top card of your library any time.
You may cast Ally spells from the top of your library.
Sacrifice Hakoda: Creatures you control get +0/+5 and gain indestructible until end of turn.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Ally

Earth Kingdom Soldier

Vigilance
When this creature enters, put a +1/+1 counter on each of up to two target creatures you control.

Flying Dolphin-Fish

Flying (This creature can't be blocked except by creatures with flying or reach.)

Teo, Spirited Glider

Flying
Whenever one or more creatures you control with flying attack, draw a card, then discard a card. When you discard a nonland card this way, put a +1/+1 counter on target creature you control.

Gran-Gran

Whenever Gran-Gran becomes tapped, draw a card, then discard a card.
Noncreature spells you cast cost {1} less to cast as long as there are three or more Lesson cards in your graveyard.

Bosco, Just a Bear

When Bosco enters, create a Food token for each legendary creature you control. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{2}{G}, Sacrifice a Food: Put two +1/+1 counters on Bosco. He gains trample until end of turn.

Marit Lage

Appa, Loyal Sky Bison

Flying
Whenever Appa enters or attacks, choose one —
• Target creature you control gains flying until end of turn.
• Airbend another target nonland permanent you control. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)

The Earth King

When The Earth King enters, create a 4/4 green Bear creature token.
Whenever one or more creatures you control with power 4 or greater attack, search your library for up to that many basic land cards, put them onto the battlefield tapped, then shuffle.

Fire Nation Warship

Reach
When this Vehicle dies, create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Clone

You may have this creature enter as a copy of any creature on the battlefield.

Island

Aang, Destined Savior

Flying
Land creatures you control have vigilance.
At the beginning of combat on your turn, earthbend 2. (Target land you control becomes a 0/0 creature with haste that's still a land. Put two +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Aang, at the Crossroads

Flying
When Aang enters, look at the top five cards of your library. You may put a creature card with mana value 4 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
When another creature you control leaves the battlefield, transform Aang at the beginning of the next upkeep.

Aang, at the Crossroads // Aang, Destined Savior

Compassionate Healer

Whenever this creature becomes tapped, you gain 1 life and scry 1. (Look at the top card of your library. You may put it on the bottom.)

Diligent Zookeeper

Each non-Human creature you control gets +1/+1 for each of its creature types, to a maximum of 10.