The Grand Calcutron

The Grand Calcutron can be your commander.
When The Grand Calcutron enters, each player's hand becomes a program (an ordered row of revealed cards).
Players can only play the first card of their program.
If a card would be put into a player's hand from anywhere, that player reveals it and places it anywhere within their program instead.
At the beginning of each player's end step, if that player's program has fewer than five cards, they draw cards equal to the difference.

Magic Word

Enchant creature
As Magic Word enters, choose a word.
Whisper the chosen word: Tap enchanted creature.

Who // What // When // Where // Why

Plains

Rock Lobster

Creatures named Scissors Lizard can't attack or block.

Loose Lips

Enchant creature
As Loose Lips enters, choose a sentence with eight or fewer words.
Enchanted creature has flying.
Whenever enchanted creature deals damage to an opponent, that player may say the chosen sentence. If they don't, you draw two cards.

Alexander Clamilton

Whenever you cast a wordy spell, scry 2. (A spell is wordy if it has four or more lines of rules text.)
{1}{R}, {T}: Choose target creature you don't control. Reveal the top card of your library. Alexander Clamilton gets +X/+0 until end of turn, where X is the number of lines of rules text of the revealed card. Alexander Clamilton fights that creature.

Ladies' Knight

Flying
Spells cast by players wearing at least one item of women's clothing cost {1} less to cast. (You can define women's clothing as you see fit. Be reasonable.)

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.

Rules Lawyer

State-based actions don't apply to you or other permanents you control. (You don't lose the game due to having 0 or less life or drawing from an empty library. Your creatures aren't destroyed due to damage or deathtouch and aren't put into a graveyard due to having 0 or less toughness. Your planeswalkers aren't put into a graveyard if they have 0 loyalty. You don't put a legendary permanent into a graveyard if you control two with the same name. Counters aren't removed from your permanents due to game rules. Permanents you control attached or combined illegally remain on the battlefield. For complete rules and regulations, see rule 704.)

Look at Me, I'm the DCI

Ban a card other than a basic land card for the rest of the match. (All cards with that name in any zone or sideboard are removed from the match.)

Thopter Pie Network

At the beginning of your upkeep, if you're eating, create a 1/1 colorless Thopter artifact creature token with flying. Use food to represent the token.
Whenever a creature token you control dies, if it's represented by food, eat it.

Johnny, Combo Player

{4}: Search your library for a card, put that card into your hand, then shuffle.

Selesnya Guildgate

This land enters tapped.
{T}: Add {G} or {W}.

Underdome

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to pay Un-costs.

Our Market Research Shows That Players Like Really Long Card Names So We Made this Card to Have the Absolute Longest Card Name Ever Elemental

Art rampage 2 (Whenever this creature becomes blocked by a creature, it gets +2/+2 for each creature in the blocker's art beyond the first.)

Bronze Calendar

Spells you cast cost {1} less to cast.
You must speak in a voice other than your normal voice.
When you speak in your normal voice, sacrifice Bronze Calendar.

Supersize

Target creature gets +3½/+3½ until end of turn.

GO TO JAIL

When GO TO JAIL enters, exile target creature an opponent controls until GO TO JAIL leaves the battlefield.
At the beginning of the upkeep of the exiled card's owner, that player rolls two six-sided dice. If they roll doubles, sacrifice GO TO JAIL.

Bursting Beebles

Bursting Beebles can't be blocked as long as defending player controls two or more nonland permanents that share an artist.

Proper Laboratory Attire

Equipped creature gets +2/+1 and has protection from die rolls. (Nothing that lets a player roll a die can block, target, deal damage to, or attach to equipped creature.)
Equip {2}

Flavor Judge

{T}: Choose target spell or ability that targets a permanent you control. Then ask a person outside the game if the story of what will happen makes sense. If they say no, sacrifice Flavor Judge and counter that spell or ability.

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."

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Prismatic Wardrobe

Destroy target nonartifact, nonland permanent that doesn't share a color with clothing worn by its controller.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Mesa Chicken

Stand up, Flap your arms, Cluck like a chicken: Mesa Chicken gains flying until end of turn.

Knight of the Hokey Pokey

First strike
{1}{W}, Do the Hokey Pokey: Prevent all damage a source of your choice would deal to Knight of the Hokey Pokey this turn. (To do the Hokey Pokey, choose an arm, a leg, or your whole self and put it in. Put it out. Put it in. Shake it all about. You do the Hokey Pokey! Turn yourself around.)

Border Guardian

Whenever you cast a silver-bordered spell, put a +1/+1 counter on Border Guardian.
Whenever you cast a black-bordered spell, Border Guardian can't be blocked this turn.
Whenever you cast a white-bordered spell, Border Guardian gains double strike until end of turn.

Emcee

Whenever another creature enters, you may stand up and say in a deep, booming voice, "Presenting . . . " and that creature's name. If you do, put a +1/+1 counter on that creature.

Forest

Island

B.O.B. (Bevy of Beebles)

As B.O.B. enters, create four 1/1 blue Beeble creature tokens.
The number of loyalty counters on B.O.B. is equal to the number of Beebles you control. (Create or sacrifice Beebles whenever B.O.B. gains or loses loyalty.)
+1: Up to X target Beebles can't be blocked this turn, where X is the number of cards in your hand.
−1: Draw a card.

Common Courtesy

Whenever a player casts a spell without asking your permission while casting it, counter that spell.
When a player asks you permission to cast a spell and you refuse, counter that spell and sacrifice Common Courtesy.

Animate Library

Enchant your library
Enchanted library is an artifact creature on the battlefield with power and toughness each equal to the number of cards in it. It's still a library.
If enchanted library would leave the battlefield, exile Animate Library instead.

Avatar of Me

This spell costs {1} more to cast for each ten years you've been alive.
Avatar of Me's power is equal to your height in feet and its toughness is equal to your American shoe size. Round to the nearest ½.
Avatar of Me is the color of your eyes.

Now I Know My ABC's

At the beginning of your upkeep, if you control permanents with names that include all twenty-six letters of the English alphabet, you win the game.

B-I-N-G-O

Trample
Whenever a player casts a spell, put a chip counter on its mana value.
B-I-N-G-O gets +9/+9 for each set of three numbers in a row with chip counters on them.

Spy Eye

Flying
Whenever Spy Eye deals combat damage to a player, you may draw a card from that player's library.

Blurry Beeble

Blurry (This creature can be blocked only if defending player was wearing glasses as it was cast.)
Whenever Blurry Beeble deals combat damage to a player, you may draw a card. If you do, discard a card.

Stone-Cold Basilisk

Whenever Stone-Cold Basilisk blocks or becomes blocked by a creature with fewer letters in its name, destroy that creature at end of combat. (Punctuation and spaces aren't letters.)
Whenever an opponent reads Stone-Cold Basilisk, that player is turned to stone until end of turn. Stoned players can't attack, block, cast spells, or activate abilities.

Topsy Turvy

The phases of each player's turn are reversed. (The phases are, in reverse order, ending, second main, combat, first main, and beginning.)
As long as there are more than two players in the game, the turn order is reversed.

City of Ass

City of Ass enters tapped.
{T}: Add one and one-half mana of any one color.

Squirrel Dealer

When Squirrel Dealer enters, ask a person outside the game "Do you like Squirrels?" If they do, create a 1/1 green Squirrel creature token.

Mouth to Mouth

Choose target opponent and target creature they control. You and that player have a breath-holding contest. If you win, you gain control of that creature.