Imposter Mech

You may have Imposter Mech enter as a copy of a creature an opponent controls, except it's a Vehicle artifact with crew 3 and it loses all other card types.
Crew 3

Grand Crescendo

Create X 1/1 green and white Citizen creature tokens. Creatures you control gain indestructible until end of turn.

Kasla, the Broken Halo

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.)
Flying, vigilance, haste
Whenever you cast another spell that has convoke, scry 2, then draw a card.

Crackleburr

{U/R}{U/R}, {T}, Tap two untapped red creatures you control: Crackleburr deals 3 damage to any target.
{U/R}{U/R}, {Q}, Untap two tapped blue creatures you control: Return target creature to its owner's hand. ({Q} is the untap symbol.)

Opposition

Tap an untapped creature you control: Tap target artifact, creature, or land.

Meeting of Minds

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.)
Draw two cards.

Venerated Loxodon

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.)
When Venerated Loxodon enters, put a +1/+1 counter on each creature that convoked it.

Divine Visitation

If one or more creature tokens would be created under your control, that many 4/4 white Angel creature tokens with flying and vigilance are created instead.

Augusta, Dean of Order

Other tapped creatures you control get +1/+0.
Other untapped creatures you control get +0/+1.
Whenever you attack, untap each creature you control, then tap any number of creatures you control.

Plargg, Dean of Chaos

{T}, Discard a card: Draw a card.
{4}{R}, {T}: Reveal cards from the top of your library until you reveal a nonlegendary, nonland card with mana value 3 or less. You may cast that card without paying its mana cost. Put all revealed cards not cast this way on the bottom of your library in a random order.

Plargg, Dean of Chaos // Augusta, Dean of Order

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Zephyr Singer

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.)
Flying, vigilance
When Zephyr Singer enters, put a flying counter on each creature that convoked it.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Springleaf Drum

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

Izzet Signet

Joyful Stormsculptor

When Joyful Stormsculptor enters, create two 1/1 blue and red Elemental creature tokens.
Whenever you cast a spell that has convoke, Joyful Stormsculptor deals 1 damage to each opponent and each battle they protect.

Saint Traft and Rem Karolus

Whenever Saint Traft and Rem Karolus becomes tapped, create a 1/1 red Human creature token if this is the first time this ability has resolved this turn. If it's the second time, create a 1/1 blue Spirit creature token with flying. If it's the third time, create a 4/4 white Angel creature token with flying.
Whenever you cast a spell that has convoke, untap Saint Traft and Rem Karolus.

Hour of Reckoning

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.)
Destroy all nontoken creatures.

Azorius Signet

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Caetus, Sea Tyrant of Segovia

Noncreature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
At the beginning of your end step, untap up to four target creatures.

Invasion of Segovia

(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 Invasion of Segovia enters, create two 1/1 blue Kraken creature tokens with trample.

Invasion of Segovia // Caetus, Sea Tyrant of Segovia

Parhelion II

Flying, first strike, vigilance
Whenever Parhelion II attacks, create two 4/4 white Angel creature tokens with flying and vigilance that are attacking.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Clever Concealment

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.)
Any number of target nonland permanents you control phase out. (Treat them and anything attached to them as though they don't exist until your next turn.)

Aerial Surveyor

Flying
Whenever Aerial Surveyor attacks, if defending player controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.
Crew 2

Martial Coup

Create X 1/1 white Soldier creature tokens. If X is 5 or more, destroy all other creatures.

Flockchaser Phantom

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.)
Flying, vigilance
Whenever Flockchaser Phantom attacks, the next spell you cast this turn has convoke.

Knight-Errant of Eos

Convoke
When Knight-Errant of Eos enters, look at the top six cards of your library. You may reveal up to two creature cards with mana value X or less from among them, where X is the number of creatures that convoked Knight-Errant of Eos. Put the revealed cards into your hand, then shuffle.

Chant of Vitu-Ghazi

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.)
Prevent all damage that would be dealt by creatures this turn. You gain life equal to the damage prevented this way.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Wildfire Awakener

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.)
When Wildfire Awakener enters, create X 1/1 red Elemental creature tokens with "Whenever this creature becomes tapped, it deals 1 damage to target player."

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Jeskai Ascendancy

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.
Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

Boros Signet

Ephemeral Shields

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.)
Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Stonybrook Schoolmaster

Whenever Stonybrook Schoolmaster becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Wand of the Worldsoul

Wand of the Worldsoul enters tapped.
{T}: Add {W}.
{T}: The next spell you cast this turn has convoke.

Daring Thief

Inspired — Whenever Daring Thief becomes untapped, you may exchange control of target nonland permanent you control and target permanent an opponent controls that shares a card type with it.

Throne of the God-Pharaoh

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

Skrelv's Hive

At the beginning of your upkeep, you lose 1 life and create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."
Corrupted — As long as an opponent has three or more poison counters, creatures you control with toxic have lifelink.

Secure the Wastes

Create X 1/1 white Warrior creature tokens.

Brudiclad, Telchor Engineer

Creature tokens you control have haste.
At the beginning of combat on your turn, create a 2/1 blue Phyrexian Myr artifact creature token. Then you may choose a token you control. If you do, each other token you control becomes a copy of that token.

Moonsnare Prototype

{T}, Tap an untapped artifact or creature you control: Add {C}.
Channel — {4}{U}, Discard Moonsnare Prototype: The owner of target nonland permanent puts it on their choice of the top or bottom of their library.

Burn at the Stake

As an additional cost to cast this spell, tap any number of untapped creatures you control.
Burn at the Stake deals damage to any target equal to three times the number of creatures tapped this way.

Fallowsage

Whenever Fallowsage becomes tapped, you may draw a card.

Shared Discovery

As an additional cost to cast this spell, tap four untapped creatures you control.
Draw three cards.

Rumor Gatherer

Alliance — Whenever another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.