Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Herald's Horn

As this artifact enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Nimana Skydancer

Flash
Flying
When this creature enters, target opponent mills two cards. (They put the top two cards of their library into their graveyard.)

Cover of Darkness

As this enchantment enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Metallic Mimic

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Venom, Deadly Devourer

Vigilance, menace
{3}: Exile target creature card from a graveyard. When you do, put X +1/+1 counters on target Symbiote, where X is the exiled card's toughness.

Visions of Dread

Target opponent puts a creature card of their choice from their graveyard onto the battlefield under your control.
Flashback {8}{B}{B}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Woodlurker Mimic

Whenever you cast a spell that's both black and green, this creature has base power and toughness 4/5 until end of turn and gains wither until end of turn. (It deals damage to creatures in the form of -1/-1 counters.)

Banner of Kinship

As this artifact enters, choose a creature type. This artifact enters with a fellowship counter on it for each creature you control of the chosen type.
Creatures you control of the chosen type get +1/+1 for each fellowship counter on this artifact.

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Conspiracy

As this enchantment enters, choose a creature type.
Creatures you control are the chosen type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Lifecraft Engine

As this Vehicle enters, choose a creature type.
Vehicle creatures you control are the chosen creature type in addition to their other types.
Each creature you control of the chosen type other than this Vehicle gets +1/+1.
Crew 3

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Masked Vandal

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

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Realmwalker

Changeling (This card is every creature type.)
As this creature 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.

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.

Activated Sleeper

Flash
You may have this creature enter as a copy of any creature card in a graveyard that was put there from the battlefield this turn, except it's a Phyrexian in addition to its other types.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Three Tree Mascot

Changeling (This card is every creature type.)
{1}: Add one mana of any color. Activate only once each turn.

Venomous Changeling

Changeling (This card is every creature type.)
Deathtouch

Skeletal Changeling

Changeling (This card is every creature type.)
{1}{B}: Regenerate this creature.