Aardvark Sloth

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

Plains

Sokka, Wolf Cove's Protector

Vigilance (Attacking doesn't cause this creature to tap.)

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.

Aang, Air Nomad

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)
Other creatures you control have vigilance.

Appa, Aang's Companion

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Appa attacks, another target attacking creature without flying gains flying until end of turn.

Tundra Wall

Razor Rings

Razor Rings deals 4 damage to target attacking or blocking creature. You gain life equal to the excess damage dealt this way.

Katara, Heroic Healer

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Katara enters, put a +1/+1 counter on each other creature you control.

Sledding Otter-Penguin

{3}: Put a +1/+1 counter on this creature.

Aang's Defense

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

Wolf Cove Villager

Path to Redemption

Enchant creature
Enchanted creature can't attack or block.
{5}, Sacrifice this Aura: Exile enchanted creature. Create a 1/1 white Ally creature token. Activate only during your turn.