Lilypad Village

{T}: Add {C}.
{T}: Add {U}. Spend this mana only to cast a creature spell.
{U}, {T}: Surveil 2. Activate only if a Bird, Frog, Otter, or Rat entered the battlefield under your control this turn.

Alania, Divergent Storm

Whenever you cast a spell, if it's the first instant spell, the first sorcery spell, or the first Otter spell other than Alania you've cast this turn, you may have target opponent draw a card. If you do, copy that spell. You may choose new targets for the copy.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Island

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Mountain

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.