Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Simic Locket

{T}: Add {G} or {U}.
{G/U}{G/U}{G/U}{G/U}, {T}, Sacrifice this artifact: Draw two cards.

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

{T}: Add {C}.
{T}: Add {G} or {U}. This artifact deals 1 damage to you.

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

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

This land enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

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

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice this land: Draw a card.

{T}: Add {G} or {U}.
{G}{U}, {T}, Sacrifice this artifact: Draw a card.