Strength-Testing Hammer

Whenever equipped creature attacks, roll a six-sided die. That creature gets +X/+0 until end of turn, where X is the result. Then if it has the greatest power or is tied for greatest power among creatures on the battlefield, draw a card.
Equip {3}

Surprise Party

When Surprise Party enters, yell "Surprise!" and put onto the battlefield any number of printed Clown Robot tokens that aren't touching each other, that you hid on the battlefield before you cast Surprise Party, and that weren't spotted by an opponent before you cast Surprise Party.
Robots you control get +1/+0 and have vigilance.

Priority Boarding

Whenever you roll a die, you may reveal the top card of your library. Do this only once each turn. Whenever you reveal a card with mana value less than the result this way, you may exile it. If you do, you may play it this turn.

The Big Top

{T}: Add one mana of any color that appears on your top. (A top is an outerwear garment worn on the upper body.)

Tempered Steel

Artifact creatures you control get +2/+2.

Well Done

Well Done deals 5 damage to target creature. If that creature is rare or mythic rare, Well Done deals 3 damage to that creature's controller.

Krark's Other Thumb

If you would roll a die, instead roll two of those dice and ignore one of those results.

Main Event Horizon

As an additional cost to cast this spell, choose A through M or N through Z.
Destroy each creature whose name begins with a letter in the chosen range.

Comet, Stellar Pup

0: Roll a six-sided die.
1 or 2 — [+2], then create two 1/1 green Squirrel creature tokens. They gain haste until end of turn.
3 — [−1], then return a card with mana value 2 or less from your graveyard to your hand.
4 or 5 — Comet, Stellar Pup deals damage equal to the number of loyalty counters on him to a creature or player, then [−2].
6 — [+1], and you may activate Comet, Stellar Pup's loyalty ability two more times this turn.

Clown Car

When Clown Car enters, roll X six-sided dice. For each odd result, create a 1/1 white Clown Robot artifact creature token. For each even result, put a +1/+1 counter on Clown Car.
Crew 2

Intangible Virtue

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

Robo-Piñata

When Robo-Piñata dies, choose one —
• You get {TK}{TK}.
• You may put a sticker on a nonland permanent you own.

Circuits Act

Roll three six-sided dice. For each different result, create a 1/1 white Clown Robot artifact creature token.

Park Map

{1}, Sacrifice Park Map: Search your library for a land card that doesn't have the same art as a permanent you control, reveal it, put it into your hand, then shuffle.

Brazen Dwarf

Whenever you roll one or more dice, Brazen Dwarf deals 1 damage to each opponent.

T.A.P.P.E.R.

{T}, Tap an untapped creature you control that has a hat: Tap target creature.

Ticking Mime Bomb

When Ticking Mime Bomb enters, without speaking or indicating any specific creature, pantomime to a person outside the game, then they choose a creature you don't control. Ticking Mime Bomb deals damage equal to twice the number of Robots you control to the chosen creature.

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.

Bar Entry

Choose one —
• Destroy target creature with power 4 or greater.
• Destroy target creature with any part of its head higher than the bar. (Align the tops of both cards to check.)

Starlight Spectacular

Parade! — At the beginning of combat on your turn, choose creatures you control one at a time until each creature you control has been chosen. Each of those creatures gets +1/+1 until end of turn for each creature chosen before it. (Places everyone! The first creature in line gets +0/+0.)

Clowning Around

Create two 1/1 white Clown Robot artifact creature tokens, then roll a six-sided die. If the result is equal to or less than the number of Robots you control, create a 1/1 white Clown Robot artifact creature token.

Ferocity of the Wilds

Attacking non-Human creatures you control get +1/+0 and have trample.

Pie-roclasm

Pie-roclasm deals π damage to each non-Clown creature. (How to calculate π isn't important. It's a smidgen more than 3.)

Omniclown Colossus

Affinity for Clowns (This spell costs {1} less to cast for each Clown you control.)
Trample

Omniclown Colossus // Pie-roclasm

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Sol Ring

Pietra, Crafter of Clowns

Haste
Robots you control get +1/+1.
{R}{W}, {T}, Tell a joke you haven't told this game to someone outside the game: Create a 1/1 white Clown Robot artifact creature token. If that person laughed, the token gains haste until end of turn.

Autograph Book

Autograph Book enters with a page counter on it for each person who has signed it.
{3}, {T}, Remove a page counter from Autograph Book: Draw a card.

Slight Malfunction

Choose one —
• Destroy target artifact.
• Roll a six-sided die. When you do, Slight Malfunction deals 1 damage to each of up to X target creatures, where X is the result.

Trigger Happy

Choose a triggered ability of target permanent. It triggers. You control that ability.

Devil K. Nevil

Haste
When Devil K. Nevil enters, jump it over any number of creatures. If it clears those creatures, put that many +1/+1 counters on it. (You can see a jumping demonstration at DevilKNevil.com.)

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Ticket Turbotubes

{T}: Add one mana of any color.
{3}, {T}: You get {TK} (a ticket counter).

Non-Human Cannonball

When Non-Human Cannonball dies, roll a six-sided die. If the result is 4 or less, Non-Human Cannonball deals that much damage to you.

Impounding Lot-Bot

When Impounding Lot-Bot enters, you may say "INCARCERATE!" in a robot voice. If you do, exile another target artifact or enchantment until Impounding Lot-Bot leaves the battlefield.

D00-DL, Caricaturist

When D00-DL, Caricaturist enters, create a 4/4 colorless Sketch creature token, which you have fifteen seconds to draw. The token has flying if it has wings in its art. The same is true for first strike and a sword, vigilance and a shield, menace and mean eyes, trample and horns, deathtouch and claws, lifelink and fangs, and haste and footwear.

Arcane Signet

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

Blue Ribbon

When Blue Ribbon enters, ask a person outside the game which creature you control is most deserving of a blue ribbon. Attach Blue Ribbon to that creature.
Equipped creature has best in show. (Whenever another creature becomes the target of a spell or ability you control, you may copy that spell or ability. If you do, the copy targets this creature.)
Equip {3}

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Organic Extinction

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Destroy all nonartifact creatures.

Barbarian Class

(Gain the next level as a sorcery to add its ability.)
If you would roll one or more dice, instead roll that many dice plus one and ignore the lowest roll.
{1}{R}: Level 2
Whenever you roll one or more dice, target creature you control gets +2/+0 and gains menace until end of turn.
{2}{R}: Level 3
Creatures you control have haste.

Wyll, Blade of Frontiers

If you would roll one or more dice, instead roll that many dice plus one and ignore the lowest roll.
Whenever you roll one or more dice, put a +1/+1 counter on Wyll, Blade of Frontiers.
Choose a Background (You can have a Background as a second commander.)

Assembled Ensemble

Vigilance
Assembled Ensemble's power is equal to the number of Robots you control.
Whenever you cast a spell with an artifact creature in its art, create a 1/1 white Clown Robot artifact creature token.

Form of the Approach of the Second Sun

When this enchantment enters, you gain 7 life. You become a card until you leave your library or that library is shuffled. Put yourself seventh from the top, balancing the cards on top of you on your head.
When you draw yourself, you win the game.
When one or more cards fall off your head, exile them and all cards on your head, then sacrifice this enchantment.

Jor Kadeen, the Prevailer

First strike
Metalcraft — Creatures you control get +3/+0 as long as you control three or more artifacts.

Celebr-8000

At the beginning of combat on your turn, roll two six-sided dice. For each result of 1, Celebr-8000 gets +1/+1 until end of turn. For each other result, it gains the indicated ability until end of turn. If you rolled doubles, it also gains double strike until end of turn.
• 2 — menace
• 3 — vigilance
• 4 — lifelink
• 5 — flying
• 6 — indestructible

Nearby Planet

Rangeling (This card is every land type, including Plains, Island, Swamp, Mountain, Forest, Desert, Gate, Lair, Locus, and all those Urza's ones.)
Nearby Planet enters tapped.
When Nearby Planet enters, sacrifice it unless you pay {1}.

Park Re-Entry

Return up to two target creature cards that each have a hat and/or mana value 3 or less from your graveyard to the battlefield.

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.

One-Clown Band

{2}{R}: Target Robot gets +2/+0 until end of turn.

Vexing Puzzlebox

Whenever you roll one or more dice, put a number of charge counters on Vexing Puzzlebox equal to the result.
{T}: Add one mana of any color. Roll a d20.
{T}, Remove 100 charge counters from Vexing Puzzlebox: Search your library for an artifact card, put that card onto the battlefield, then shuffle.

Inspiring Leader

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

Don't Try This at Home

If a hot source you control would deal damage to a permanent or player, it deals that much damage plus 1 instead. (Something is hot if it has hot things in its art, like fire or explosions.)
{1}{R}, Sacrifice Don't Try This at Home: It deals damage equal to twice the number of hot cards in your graveyard to target creature or planeswalker.

A Good Day to Pie

Tap up to two target creatures.
Whenever you put a name sticker on a creature, you may return A Good Day to Pie from your graveyard to your hand.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic 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.

Art Appreciation

Put an art sticker on a nonland permanent you own. Then ask a person outside the game to rate its new art on a scale from 1 to 5, where 5 is the best. When they rate the art, up to that many target creatures can't block this turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Neyali, Suns' Vanguard

Attacking tokens you control have double strike.
Whenever one or more tokens you control attack a player, exile the top card of your library. During any turn you attacked with a token, you may play that card.

Souvenir T-Shirt

Gear Up, sponsored by Wizards of the Coast — As Souvenir T-Shirt enters, roll two six-sided dice. For each Magic-branded item you're wearing, roll an additional six-sided die. Choose two of those results.
Equipped creature gets +X/+Y, where X is the first chosen result and Y is the second.
Equip {4}

Plains

Gobsmacked

Enchant nonland permanent
As Gobsmacked enters, choose a person outside the game.
As long as you can see the chosen person from your seat, enchanted permanent can't attack or block, and its activated abilities can't be activated.

Juggletron

Trample
Whenever Juggletron attacks, you may put an art sticker on it.
Juggletron gets +3/+0 for each item in its art that's not touching Juggletron, another item, or the card frame.