Island

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.

Sokka, Lateral Strategist

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

Messenger Hawk

Flying
When this creature enters, create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")
This creature gets +2/+0 as long as you've drawn two or more cards this turn.

Whirlwind Technique

Target player draws two cards, then discards a card.
Airbend up to two target creatures. (To airbend a creature, exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)

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.")

Turtle-Seals

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

It'll Quench Ya!

Counter target spell unless its controller pays {2}.

Rowdy Snowballers

When this creature enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Sokka's Haiku

Counter target spell.
Draw a card, then mill three cards.
Untap target land.

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.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Tiger-Seal

Vigilance
At the beginning of your upkeep, tap this creature.
Whenever you draw your second card each turn, untap this creature.

Thriving Isle

This land enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.