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

How Is This a Par Three?!

Whenever you cast a spell, you may have target player mill X cards, where X is the number of words in that spell's name.

Fluros of Myra's Marvels

As Fluros of Myra's Marvels enters, choose a number greater than 0.
Whenever you cast a spell with power, toughness, or loyalty equal to the chosen number, target artifact or creature becomes an artifact creature with base power and toughness X/X until end of turn, where X is the chosen number.
Partner

Ignacio of Myra's Marvels

As Ignacio of Myra's Marvels enters, choose armor, blood, book, bottle, fang, fire, scroll, spear, sword, or water.
Whenever you cast a spell with the chosen object in its art, create two Treasure tokens.
Partner (You can have two commanders if both have partner.)

Goblin Blastronauts

When Goblin Blastronauts enters, open an Attraction.
Whenever you roll a 6, you may copy the spell, ability, or Attraction visit that caused you to roll that die. You may choose new targets for the copy.

Circuits Act

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

Vedalken Squirrel-Whacker

As Vedalken Squirrel-Whacker enters, roll a six-sided die twice. Its base power becomes the first result and its base toughness becomes the second result.
If you would roll one or more six-sided dice, instead roll them and you may exchange one result with Vedalken Squirrel-Whacker's base power or base toughness.

One-Clown Band

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

Monitor Monitor

When Monitor Monitor enters, open an Attraction. (Put the top card of your Attraction deck onto the battlefield.)
Once each turn, you may pay {1} to reroll one or more dice you rolled.

Bag Check

Counter target spell, then ask a person outside the game if that spell looks dangerous to them. If they say yes, draw a card, then discard a card.

Goblin Cruciverbalist

Haste
When Goblin Cruciverbalist enters, create a colorless artifact token named your choice of A, E, I, O, or U.
Whenever Goblin Cruciverbalist attacks, using the first letters of the names of permanents you control, spell a word you haven't spelled this game. It gets +1/+0 until end of turn for each letter in that word.

Rock Star

Reach
When Rock Star enters, you may discard a card. If you do, reveal the top five cards of your library. Ask a person outside the game to choose which of them is most like a rock band. Put that card into your hand and the rest on the bottom of your library in a random order.

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.

Treacherous Trapezist

Flying
Whenever you cast an alliterative spell, scry 2. (Anything with two or more capitalized words in its name that begin with the same letter is alliterative.)
Other alliterative creatures you control have flying.