Mark Rosewater

Few understand the DCI's rigorous decision-making process.

Look at Me, I'm the DCI

Ban one card, other than a basic land, for the remainder of the match. (For the remainder of the match, each player removes from the game all copies of that card in play or in any graveyard, hand, library, or sideboard.)

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.)

Auspicious Aquarium

Each creature you control that's a Clamfolk, Crab, Crocodile, Fish, Homarid, Jellyfish, Kraken, Leviathan, Lobster, Merfolk, Nautilus, Octopus, Otter, Oyster, Seal, Serpent, Shark, Shrimp, Sponge, Squid, Starfish, Trilobite, Turtle, Walrus, or Whale gets +2/+2.
At the beginning of your upkeep, if you control twelve different creatures from the above list and don't control a Brushwagg, you win the game.

Bicycle Elemental

As this creature enters, choose a word.
Each card in your hand with the chosen word in its name, type line, and/or rules text has cycling {2}. ({2}, Discard that card: Draw a card.)
Whenever you cycle a card, put a +1/+1 counter on this creature.

In Residence

When this enchantment enters, search your library for a legendary creature card with mana value X or less, exile it, then shuffle.
At the beginning of your first main phase, you may introduce the exiled card using an introduction you haven't used this game. If you do, put that card onto the battlefield. It gains haste. Exile that creature at the beginning of the next end step.

Spaghetti Junction

{T}: Add {C}.
{4}, {T}: Create a 3/2 colorless Vehicle artifact token with crew 1.
Whenever a Vehicle you control attacks, put a traffic counter on this land.
When this land has eight traffic counters on it, sacrifice it. If you do, create Atlantakul, a legendary 20/20 colorless Eldrazi creature token with annihilator 2.

All-You-Can-Eat Buffet

You may look at the top card of your library any time.
You may play lands and cast creature spells from the top of your library.
The top card of your library is a Food token. It's still a card. (It has "{2},{T}, Sacrifice this token: You gain 3 life.")

Second City

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast your second spell in a turn. When that mana is spent, create a Deep Dish Pizza token. (It's a Food artifact with "{3}, {T}, Sacrifice this token: You gain 3 life and draw a card.")

Convention Maro

Whenever you cast a spell that [CHOICE A], create a green Elemental creature token named Maro with "This creature's power and toughness are each equal to the number of [CHOICE B]."
— As you create your deck, choose an [A] and a [B] —
• [A1] "is an Elemental" | [A2] "has a watermark or landscape orientation" | [A3] "targets a creature you control"
• [B1] "cards in your hand" | [B2] "card types among cards in your graveyard" | [B3] "artists among nonland, nontoken permanents you control"

Maro's Gone Nuts

Double any effect that doubles. (It quadruples.)