Tangleroot

Whenever a player casts a creature spell, that player adds {G}.

False Dawn

Until end of turn, spells and abilities you control that would add colored mana instead add that much white mana. Until end of turn, you may spend white mana as though it were mana of any color.
Draw a card.

Kor Skyfisher

Flying
When this creature enters, return a permanent you control to its owner's hand.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Hamza, Guardian of Arashin

This spell costs {1} less to cast for each creature you control with a +1/+1 counter on it.
Creature spells you cast cost {1} less to cast for each creature you control with a +1/+1 counter on it.

The Wind Crystal

White spells you cast cost {1} less to cast.
If you would gain life, you gain twice that much life instead.
{4}{W}{W}, {T}: Creatures you control gain flying and lifelink until end of turn.

Aviary Mechanic

When this creature enters, you may return another permanent you control to its owner's hand.

Whitemane Lion

Flash
When this creature enters, return a creature you control to its owner's hand.