Grusilda, Monster Masher

Combined, enchanted, and equipped creatures you control have menace.
{3}{B}{R}, {T}: Put two target creature cards from graveyards onto the battlefield combined into one creature under your control. (Its power is equal to their total power, its toughness is equal to their total toughness, and it has their names, mana costs, types, text boxes, etc.)

Infinity Elemental

Painiac

At the beginning of your upkeep, roll a six-sided die. Painiac gets +X/+0 until end of turn, where X is the result.

Hoisted Hireling

Hoisted Hireling has flying as long as it's being held above the battlefield.

Buzzing Whack-a-Doodle

As Buzzing Whack-a-Doodle enters, you and an opponent each secretly choose Whack or Doodle. Then those choices are revealed. If the choices match, Buzzing Whack-a-Doodle has that ability. Otherwise, it has Buzz.
• Whack — {T}: Target player loses 2 life.
• Doodle — {T}: You gain 3 life.
• Buzz — {2}, {T}: Draw a card.

Yet Another Aether Vortex

All creatures have haste.
Players play with the top card of their libraries revealed.
Noninstant, nonsorcery cards on top of a library are on the battlefield under their owner's control in addition to being in that library.

Lobe Lobber

Equipped creature has "{T}: This creature deals 1 damage to target player or planeswalker. Roll a six-sided die. On a 5 or higher, untap it."
Equip {2}

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.

When Fluffy Bunnies Attack

Target creature gets -X/-X until end of turn, where X is the number of times the letter of your choice appears in that creature's name.

Modular Monstrosity

Whenever an opponent casts a spell, you have five seconds to choose a keyword you haven't chosen for a card named Modular Monstrosity today that's been printed on a creature card. If you do, Modular Monstrosity gains that ability. Otherwise, Modular Monstrosity loses all keyword abilities.

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.

Hammer Helper

Gain control of target creature until end of turn. Untap that creature and roll a six-sided die. Until end of turn, it gains haste and gets +X/+0, where X is the result.

Finders, Keepers

Destroy target creature, then assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Squirrel-Powered Scheme

Increase the result of each die you roll by 2.

Party Crasher

Haste
You can attack with Party Crasher once each combat during each opponent's turn.

Split Screen

When Split Screen enters, shuffle your library and deal it into four libraries. If anything refers to your library, choose one of your libraries for it.
Play with your libraries' top cards revealed.
When Split Screen leaves the battlefield, shuffle your libraries together.

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.

Inhumaniac

At the beginning of your upkeep, roll a six-sided die. On a 3 or 4, put a +1/+1 counter on Inhumaniac. On a 5 or higher, put two +1/+1 counters on it. On a 1, remove all +1/+1 counters from Inhumaniac.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Over My Dead Bodies

Creature cards in graveyards can attack and block as though they were on the battlefield, can block or be blocked only by creature cards in graveyards, are Zombies in addition to their other types, and have undeathtouch. (If they would deal damage to a creature card, exile that creature card instead.)
Creature cards in your graveyard have haste.

Super-Duper Death Ray

Trample (This spell can deal excess damage to its target's controller.)
Super-Duper Death Ray deals 4 damage to target creature.

Sword of Dungeons & Dragons

Equipped creature gets +2/+2 and has protection from Rogues and from Clerics.
Whenever equipped creature deals combat damage to a player, create a 4/4 gold Dragon creature token with flying and roll a d20 (a twenty-sided die). If you roll a 20, repeat this process.
Equip {2}

Skull Saucer

Flying
When Skull Saucer enters, destroy target creature and put your head on the table. Sacrifice Skull Saucer when your head stops touching the table.

Burning Cinder Fury of Crimson Chaos Fire

Whenever any player taps a permanent, that player chooses one of their opponents. The chosen player gains control of that permanent at the beginning of the next end step.
At the beginning of each player's end step, if that player didn't tap any nonland permanents that turn, Burning Cinder Fury of Crimson Chaos Fire deals 3 damage to that player.

The Big Idea

{2}{B/R}{B/R}, {T}: Roll a six-sided die. Create a number of 1/1 red Brainiac creature tokens equal to the result.
Tap three untapped Brainiacs you control: The next time you would roll a six-sided die, instead roll two six-sided dice and use the total of those results.

Steady-Handed Mook

Deathtouch
When Steady-Handed Mook enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

The Ultimate Nightmare of Wizards of the Coast® Customer Service

The Ultimate Nightmare of Wizards of the Coast® Customer Service deals X damage to each of Y target creatures and Z target players or planeswalkers.

capital offense

target creature gets -x/-x until end of turn, where x is the number of times a capital letter appears in its rules text. (ignore reminder text and flavor text.)

Mad Science Fair Project

{T}: Roll a six-sided die. On a 3 or lower, target player adds {C}. Otherwise, that player adds one mana of any color they choose.

Krark's Other Thumb

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

Water Gun Balloon Game

As Water Gun Balloon Game enters, each player puts a pop! counter on "0."
Whenever a player casts a spell, move that player's pop! counter up one.
Whenever a player's pop! counter hits "5," that player creates a 5/5 pink Giant Teddy Bear creature token and resets all pop! counters to "0."

Stop That

Target player discards a card.
Gotcha — If an opponent audibly flicks the cards in their hand, you may say "Gotcha!" When you do, return Stop That from your graveyard to your hand.