Turntimber Ranger

Whenever this creature or another Ally you control enters, you may create a 2/2 green Wolf creature token. If you do, put a +1/+1 counter on this creature.

Tale of Katara and Toph

Creatures you control have "Whenever this creature becomes tapped for the first time during each of your turns, put a +1/+1 counter on it."

Azula, Ruthless Firebender

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Whenever Azula attacks, you may discard a card. Then you get an experience counter for each player who discarded a card this turn.
{2}{B}: Until end of turn, Azula gets +1/+1 for each experience counter you have and gains menace.

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.

Great Divide Guide

Each land and Ally you control has "{T}: Add one mana of any color."

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Katara, the Fearless

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

South Pole Voyager

Whenever this creature or another Ally you control enters, you gain 1 life. If this is the second time this ability has resolved this turn, draw a card.

Sokka, Lateral Strategist

Vigilance
Whenever Sokka and at least one other creature attack, draw a card.

Plains

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.

Flowering of the White Tree

Legendary creatures you control get +2/+1 and have ward {1}.
Nonlegendary creatures you control get +1/+1.

Toph, Earthbending Master

Landfall — Whenever a land you control enters, you get an experience counter.
Whenever you attack, earthbend X, where X is the number of experience counters you have. (Target land you control becomes a 0/0 creature with haste that's still a land. Put X +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Aang and La, Ocean's Fury

Reach, trample
Whenever Aang and La attack, put a +1/+1 counter on each tapped creature you control.

Aang, Swift Savior

Flash
Flying
When Aang enters, airbend up to one other target creature or spell. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Waterbend {8}: Transform Aang.

Aang, Swift Savior // Aang and La, Ocean's Fury

Ondu Cleric

Whenever this creature or another Ally you control enters, you may gain life equal to the number of Allies you control.

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sea Gate Loremaster

{T}: Draw a card for each Ally you control.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Katara, Waterbending Master

Whenever you cast a spell during an opponent's turn, you get an experience counter.
Whenever Katara attacks, you may draw a card for each experience counter you have. If you do, discard a card.

Island

Forest

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Toph, the Blind Bandit

When Toph 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.)
Toph's power is equal to the number of +1/+1 counters on lands you control.

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

Aang, Airbending Master

When Aang enters, airbend another target creature. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever one or more creatures you control leave the battlefield without dying, you get an experience counter.
At the beginning of your upkeep, create a 1/1 white Ally creature token for each experience counter you have.

Permission Denied

Counter target noncreature spell. Your opponents can't cast noncreature spells this turn.

Kabira Evangel

Whenever this creature or another Ally you control enters, you may choose a color. If you do, Allies you control gain protection from the chosen color until end of turn.

Harabaz Druid

{T}: Add X mana of any one color, where X is the number of Allies you control.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Appa, Steadfast Guardian

Flash
Flying
When Appa enters, airbend any number of other target nonland permanents you control. (Exile them. While each one is exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever you cast a spell from exile, create a 1/1 white Ally creature token.

Zuko, Firebending Master

First strike
Firebending X, where X is the number of experience counters you have. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)
Whenever you cast a spell during combat, you get an experience counter.

Biorganic Carapace

When this Equipment enters, attach it to target creature you control.
Equipped creature gets +2/+2 and has "Whenever this creature deals combat damage to a player, draw a card for each modified creature you control." (Equipment, Auras you control, and counters are modifications.)
Equip {2}

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.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Appa, the Vigilant

Flying, vigilance
Whenever Appa or another Ally you control enters, creatures you control get +1/+1 and gain flying and vigilance until end of turn.