Beastcaller Savant

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

Lifeblood Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature dies, you gain life and draw cards equal to its power.

Lifespring Druid

Blossom-Clad Werewolf

{T}: Add two mana of any one color.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Weaver of Blossoms

{T}: Add one mana of any color.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Weaver of Blossoms // Blossom-Clad Werewolf

Sol Ring

Humble Naturalist

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

Silhana Starfletcher

Reach (This creature can block creatures with flying.)
As this creature enters, choose a color.
{T}: Add one mana of the chosen color.

Stumpsquall Hydra

When this creature enters, distribute X +1/+1 counters among it and any number of commanders.

Sylvok Explorer

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

Savageborn Hydra

Double strike
This creature enters with X +1/+1 counters on it.
{1}{R/G}: Put a +1/+1 counter on this creature. Activate only as a sorcery.

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If this creature has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Saruli Caretaker

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

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
This creature enters with X +1/+1 counters on it.

Rift Sower

{T}: Add one mana of any color.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Paradise Druid

This creature has hexproof as long as it's untapped. (It can't be the target of spells or abilities your opponents control.)
{T}: Add one mana of any color.

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.

Citanul Stalwart

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

Hungering Hydra

This creature enters with X +1/+1 counters on it.
This creature can't be blocked by more than one creature.
Whenever this creature is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Primordial Hydra

This creature enters with X +1/+1 counters on it.
At the beginning of your upkeep, double the number of +1/+1 counters on this creature.
This creature has trample as long as it has ten or more +1/+1 counters on it.

Llanowar Loamspeaker

{T}: Add one mana of any color.
{T}: Target land you control becomes a 3/3 Elemental creature with haste until end of turn. It's still a land. Activate only as a sorcery.

Awakened Skyclave

Vigilance, haste
As long as this creature is on the battlefield, it's a land in addition to its other types.
{T}: Add one mana of any color.

Invasion of Zendikar

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Invasion of Zendikar // Awakened Skyclave

Arcane Signet

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

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
This creature enters with X +1/+1 counters on it.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Naga Vitalist

{T}: Add one mana of any type that a land you control could produce.

Loam Dryad

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

Oasis Gardener

When this creature enters, you gain 2 life.
{T}: Add one mana of any color.

Bronze Walrus

When this creature enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{T}: Add one mana of any color.

Ornithopter of Paradise

Seasonal Ritual

Add one mana of any color. (Then exile this card. You may cast the creature later from exile.)

Rosethorn Acolyte

Rosethorn Acolyte // Seasonal Ritual

Lotus Guardian

Armored Scrapgorger

This creature gets +3/+0 as long as it has three or more oil counters on it.
{T}: Add one mana of any color.
Whenever this creature becomes tapped, exile target card from a graveyard and put an oil counter on this creature.

Apocalypse Hydra

This creature enters with X +1/+1 counters on it. If X is 5 or more, it enters with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from this creature: It deals 1 damage to any target.

Undercellar Myconid

Whenever this creature enters or dies, create a 1/1 green Saproling creature token.
{T}: Add one mana of any color.

Llanowar Tribe

Llanowar Elves

Hardbristle Bandit

{T}: Add one mana of any color.
Whenever you commit a crime, untap this creature. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Jaspera Sentinel

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

Morselhoarder

This creature enters with two -1/-1 counters on it.
Remove a -1/-1 counter from this creature: Add one mana of any color.

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, create X X/X green Hydra creature tokens.

Harvester Druid

{T}: Add one mana of any color that a land you control could produce.

Intrepid Paleontologist

{T}: Add one mana of any color.
{2}: Exile target card from a graveyard.
You may cast Dinosaur creature spells from among cards you own exiled with this creature. If you cast a spell this way, that creature enters with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)

Reclusive Taxidermist

This creature gets +3/+2 as long as there are four or more creature cards in your graveyard.
{T}: Add one mana of any color.

Forest

Wose Pathfinder

{T}: Add one mana of any color.
{6}{G}, {T}: Another target creature gets +3/+3 and gains trample until end of turn.

Hooded Hydra

This creature enters with X +1/+1 counters on it.
When this creature dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As this creature is turned face up, put five +1/+1 counters on it.

Elvish Mystic

Centaur Nurturer

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

Orochi Hatchery

This artifact enters with X charge counters on it.
{5}, {T}: Create a 1/1 green Snake creature token for each charge counter on this artifact.

Deathbloom Gardener

Deathtouch
{T}: Add one mana of any color.

Oasis Ritualist

{T}: Add one mana of any color.
{T}, Exert this creature: Add two mana of any one color. (An exerted creature won't untap during your next untap step.)

Neverwinter Hydra

As this creature enters, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.
Trample
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)

Toxicrene

Reach, deathtouch
Hypertoxic Miasma — All lands have "{T}: Add one mana of any color" and lose all other abilities.

Roxanne, Starfall Savant

Whenever Roxanne enters or attacks, create a tapped colorless artifact token named Meteorite with "When this token enters, it deals 2 damage to any target" and "{T}: Add one mana of any color."
Whenever you tap an artifact token for mana, add one mana of any type that artifact token produced.

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.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Dawnhart Rejuvenator

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Poison Dart Frog

Reach
{T}: Add one mana of any color.
{2}: This creature gains deathtouch until end of turn.

Raggadragga, Goreguts Boss

Each creature you control with a mana ability gets +2/+2.
Whenever a creature you control with a mana ability attacks, untap it.
Whenever you cast a spell, if at least seven mana was spent to cast it, untap target creature. It gets +7/+7 and gains trample until end of turn.

Gruul Signet

Vastwood Hydra

This creature enters with X +1/+1 counters on it.
When this creature dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on this creature among any number of creatures you control.

Drover of the Mighty

This creature gets +2/+2 as long as you control a Dinosaur.
{T}: Add one mana of any color.

Alloy Myr

Forsaken Thresher

At the beginning of your first main phase, add one mana of any color.

Foreboding Statue

{T}: Add one mana of any color. Put an omen counter on this creature.
At the beginning of your end step, if there are three or more omen counters on this creature, untap it, then transform it.

Foreboding Statue // Forsaken Thresher

Mountain

Draconic Disciple

{T}: Add one mana of any color.
{7}, {T}, Sacrifice this creature: Create a 5/5 red Dragon creature token with flying.

Opaline Unicorn

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Llanowar Visionary

When this creature enters, draw a card.
{T}: Add {G}.

Feral Hydra

This creature enters with X +1/+1 counters on it.
{3}: Put a +1/+1 counter on this creature. Any player may activate this ability.

Wild Cantor

({R/G} can be paid with either {R} or {G}.)
Sacrifice this creature: Add one mana of any color.