Accomplished Alchemist

{T}: Add one mana of any color.
{T}: Add X mana of any one color, where X is the amount of life you gained this turn.

Citanul Stalwart

{T}, Tap an untapped artifact or creature you control: Add one mana of any color.

Citanul Hierophants

Creatures you control have "{T}: Add {G}."

Centaur Nurturer

When this creature enters, you gain 3 life.
{T}: Add one mana of any color.

Alloy Myr

Apprentice Wizard

Copper Myr

Cormela, Glamour Thief

Haste
{1}, {T}: Add {U}{B}{R}. Spend this mana only to cast instant and/or sorcery spells.
When Cormela dies, return up to one target instant or sorcery card from your graveyard to your hand.

Blightsoil Druid

Biophagus

Genomic Enhancement — {T}: Add one mana of any color. If this mana is spent to cast a creature spell, that creature enters with an additional +1/+1 counter on it.

Atzocan Seer

{T}: Add one mana of any color.
Sacrifice this creature: Return target Dinosaur card from your graveyard to your hand.

Boreal Druid

Chandra's Embercat

{T}: Add {R}. Spend this mana only to cast an Elemental spell or a Chandra planeswalker spell.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Bog Witch

Arixmethes, Slumbering Isle

Arixmethes enters tapped with five slumber counters on it.
As long as Arixmethes has a slumber counter on it, it's a land. (It's not a creature.)
Whenever you cast a spell, you may remove a slumber counter from Arixmethes.
{T}: Add {G}{U}.

Bog Initiate

Avacyn's Pilgrim

Bighorner Rancher

Vigilance
{T}: Add an amount of {G} equal to the greatest power among creatures you control.
Sacrifice this creature: You gain life equal to the greatest toughness among other creatures you control.

Circle of Dreams Druid

{T}: Add {G} for each creature you control.

Beastcaller Savant

Haste
{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.