Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Ghostly Changeling

Changeling (This card is every creature type.)
{1}{B}: Ghostly Changeling gets +1/+1 until end of turn.

Necratog

Exile the top creature card of your graveyard: Necratog gets +2/+2 until end of turn.

Sarcatog

Exile two cards from your graveyard: Sarcatog gets +1/+1 until end of turn.
Sacrifice an artifact: Sarcatog gets +1/+1 until end of turn.

Chronatog

{0}: Chronatog gets +3/+3 until end of turn. You skip your next turn. Activate only once each turn.

Megatog

Sacrifice an artifact: Megatog gets +3/+3 and gains trample until end of turn.

Volrath's Laboratory

As Volrath's Laboratory enters, choose a color and a creature type.
{5}, {T}: Create a 2/2 creature token of the chosen color and type.

Atogatog

Sacrifice an Atog creature: Atogatog gets +X/+X until end of turn, where X is the sacrificed creature's power.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on this creature.

The Bears of Littjara

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 2/2 blue Shapeshifter creature token with changeling.
II — Any number of target Shapeshifter creatures you control have base power and toughness 4/4.
III — Choose up to one target creature or planeswalker. Each creature with power 4 or greater you control deals damage equal to its power to that permanent.

Chronatog Totem

{T}: Add {U}.
{1}{U}: Chronatog Totem becomes a 1/2 blue Atog artifact creature until end of turn.
{0}: Chronatog Totem gets +3/+3 until end of turn. You skip your next turn. Activate only once each turn and only if Chronatog Totem is a creature.

Fire-Belly Changeling

Changeling (This card is every creature type.)
{R}: Fire-Belly Changeling gets +1/+0 until end of turn. Activate no more than twice each turn.

Adaptive Automaton

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Birthing Boughs

{4}, {T}: Create a 2/2 colorless Shapeshifter creature token with changeling. (It has every creature type.)

Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Thaumatog

Sacrifice a land: Thaumatog gets +1/+1 until end of turn.
Sacrifice an enchantment: Thaumatog gets +1/+1 until end of turn.

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Fellwar Stone

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

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Psychatog

Discard a card: Psychatog gets +1/+1 until end of turn.
Exile two cards from your graveyard: Psychatog gets +1/+1 until end of turn.

Arcane Signet

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

Foratog

{G}, Sacrifice a Forest: Foratog gets +2/+2 until end of turn.

Auratog

Sacrifice an enchantment: Auratog gets +2/+2 until end of turn.

Phantatog

Sacrifice an enchantment: Phantatog gets +1/+1 until end of turn.
Discard a card: Phantatog gets +1/+1 until end of turn.

Lithatog

Sacrifice an artifact: Lithatog gets +1/+1 until end of turn.
Sacrifice a land: Lithatog gets +1/+1 until end of turn.