Sizzling Changeling

Changeling (This card is every creature type.)
When this creature dies, exile the top card of your library. Until the end of your next turn, you may play that card.

Omni-Changeling

Changeling (This card is every creature type.)
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
You may have this creature enter as a copy of any creature on the battlefield, except it has changeling.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Arcane Signet

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

Gangly Stompling

Changeling (This card is every creature type.)
Trample

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Exotic Orchard

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

Chronicle of Victory

As Chronicle of Victory enters, choose a creature type.
Creatures you control of the chosen type get +2/+2 and have first strike and trample.
Whenever you cast a spell of the chosen type, draw a card.

Chomping Changeling

Changeling (This card is every creature type.)
When this creature enters, destroy up to one target artifact or enchantment.

Springleaf Parade

When this enchantment enters, create X 1/1 colorless Shapeshifter creature tokens with changeling. (They're every creature type.)
Creature tokens you control have "{T}: Add one mana of any color."

Fellwar Stone

Personify

Exile target creature you control, then return that card to the battlefield under its owner's control. Create a 1/1 colorless Shapeshifter creature token with changeling. (It's every creature type.)

Sol Ring

Gathering Stone

As this artifact enters, choose a creature type.
Spells you cast of the chosen type cost {1} less to cast.
When this artifact enters and at the beginning of your upkeep, look at the top card of your library. If it's a card of the chosen type, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard.

Flock Impostor

Changeling (This card is every creature type.)
Flash
Flying
When this creature enters, return up to one other target creature you control to its owner's hand.

Prideful Feastling

Changeling (This card is every creature type.)
Lifelink

Mirrorform

Each nonland permanent you control becomes a copy of target non-Aura permanent.

Mutable Explorer

Changeling (This card is every creature type.)
When this creature enters, create a tapped Mutavault token. (It's a land with "{T}: Add {C}" and "{1}: This token becomes a 2/2 creature with all creature types until end of turn. It's still a land.")

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.