Katara, the Fearless

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

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.

White Lotus Reinforcements

Vigilance
Other Allies you control get +1/+1.

Tajuru Warcaller

Rally — Whenever this creature or another Ally you control enters, creatures you control get +2/+2 until end of turn.

Vastwood Animist

{T}: Target land you control becomes an X/X Elemental creature until end of turn, where X is the number of Allies you control. It's still a land.

Kor Bladewhirl

Rally — Whenever this creature or another Ally you control enters, creatures you control gain first strike until end of turn.

Umara Raptor

Flying
Whenever this creature or another Ally you control enters, you may put a +1/+1 counter on this creature.

Suki, Kyoshi Warrior

Suki's power is equal to the number of creatures you control.
Whenever Suki attacks, create a 1/1 white Ally creature token that's tapped and attacking.

Tajuru Archer

Whenever this creature or another Ally you control enters, you may have this creature deal damage to target creature with flying equal to the number of Allies you control.

Walltop Sentries

Reach, deathtouch
When this creature dies, if there's a Lesson card in your graveyard, you gain 2 life.

Makindi Patrol

Rally — Whenever this creature or another Ally you control enters, creatures you control gain vigilance until end of turn.

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.

Talus Paladin

Whenever this creature or another Ally you control enters, you may have Allies you control gain lifelink until end of turn, and you may put a +1/+1 counter on this creature.

Great Divide Guide

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

Hero of Goma Fada

Rally — Whenever this creature or another Ally you control enters, creatures you control gain indestructible until end of turn.

Jet, Rebel Leader

Whenever Jet attacks, look at the top five cards of your library. You may put a creature card with mana value 3 or less from among them onto the battlefield tapped and attacking. Put the rest on the bottom of your library in a random order.

Katara, Water Tribe's Hope

Vigilance
When Katara enters, create a 1/1 white Ally creature token.
Waterbend {X}: Creatures you control have base power and toughness X/X until end of turn. X can't be 0. Activate only during your turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

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.

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.

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.

Veteran Warleader

Veteran Warleader's power and toughness are each equal to the number of creatures you control.
Tap another untapped Ally you control: This creature gains your choice of first strike, vigilance, or trample until end of turn.

Lantern Scout

Rally — Whenever this creature or another Ally you control enters, creatures you control gain lifelink until end of turn.

Harabaz Druid

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

Sea Gate Loremaster

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

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.

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.)

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.