Zzzyxas's Abyss

At the beginning of your upkeep, destroy all nonland permanents with the first name alphabetically among nonland permanents.

Charm School

As Charm School enters, choose a color and balance Charm School on your head.
Prevent all damage that would be dealt to you by sources of the chosen color.
When Charm School falls off your head, sacrifice Charm School.

Rat in the Hat

{T}, Sacrifice Rat in the Hat: Until end of turn, you may cast target creature card that has a hat from your graveyard.

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.

Hat Trick

Target blocking or blocked creature you control gets +1/+1 and gains first strike until end of turn. If it has a hat, it gains double strike until end of turn. If you and that creature each have a hat, the creature gains triple strike until end of turn.

Farewell to Arms

As Farewell to Arms enters, choose a hand attached to an opponent's arm.
When the chosen hand isn't behind its owner's back, sacrifice Farewell to Arms. If you do, that player discards their hand . . . of cards. (The lawyers wouldn't let us do it the other way.)

Kill! Destroy!

Destroy target nonblack creature.
Gotcha — If an opponent says "kill" or "destroy," you may say "Gotcha!" When you do, return Kill! Destroy! from your graveyard to your hand.

Side Quest

Target player in an Un-game you can see from your seat gains control of target creature you control until your next turn. At the beginning of your next upkeep, put two +1/+1 counters on that creature. (A creature is on the battlefield of only the game its controller is playing.)

Sly Spy

Whenever Sly Spy deals combat damage to a player, that player loses a finger until Sly Spy leaves the battlefield. (The finger is chosen by its owner and can't roll dice or touch cards.)

Haberthrasher

Deathtouch
Whenever another creature you control that has a hat enters or a hat sticker is put on a creature you control, each opponent loses 1 life.

Exit Through the Grift Shop

Yell "Who wants a souvenir?" and announce the name of a nonland card in your graveyard. Each player in an Un-game who can hear you may bid life. You start the bidding at 0. The high bidder loses life equal to the high bid. They copy the card and may cast the copy without paying its mana cost. If you didn't win the bid, you gain life equal to the high bid and create that many Treasure tokens.

Bog Humbugs

Flying
Whenever Bog Humbugs deals combat damage, hum that many notes of a festive song. If you can, put a +1/+1 counter on Bog Humbugs.

Hangman

As Hangman enters, secretly note a word with six to eight letters.
{1}: Target player who doesn't control Hangman guesses the noted word or an unguessed letter in that word. If they guess wrong, put a +1/+1 counter on Hangman. Any player may activate this ability.
When a player guesses the noted word or all of its letters, sacrifice Hangman.

"Brims" Barone, Midway Mobster

When "Brims" Barone, Midway Mobster enters, put a +1/+1 counter on each other creature you control that has a hat.
"Brims" Barone, Midway Mobster has menace as long as you're wearing a hat.

Handcuffs

As Handcuffs enters, choose a player.
When the chosen player's hands aren't touching each other, sacrifice Handcuffs and that player sacrifices three permanents.

Rod of Spanking

{2}, {T}: Rod of Spanking deals 1 damage to target player. Then untap Rod of Spanking unless that player says "Thank you, sir. May I have another?"

Swamp

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

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

Entirely Normal Armchair

During your turn, if Entirely Normal Armchair is in your hand, you may hide it on the battlefield.
{0}: Return Entirely Normal Armchair to its owner's hand. Only your opponents may activate this ability and only if they see Entirely Normal Armchair.
{2}, Sacrifice Entirely Normal Armchair: Destroy target attacking creature.