Spike, Tournament Grinder

({B/P} can be paid with either {B} or 2 life.)
{B/P}{B/P}{B/P}{B/P}: Reveal a card you own from outside the game that has been banned or restricted in a Constructed format and put it into your hand.

The Countdown Is at One

Players play a Magic subgame, starting at 1 life and using their libraries as their decks. For the rest of the main game, if a source would deal damage to a player who didn't win the subgame, it deals double that damage to that player instead.

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.

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}

Mountain

"Rumors of My Death . . ."

{3}{B}, Exile a permanent you control with a League of Dastardly Doom watermark: Return a permanent card with a League of Dastardly Doom watermark from your graveyard to the battlefield.

Swamp

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.

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.

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.

Baron Von Count

Baron Von Count enters with a doom counter on "5."
Whenever you cast a spell with the indicated numeral in its mana cost, text box, power, or toughness, move the doom counter one numeral to the left.
When the doom counter moves from "1," destroy target player and put that doom counter on "5."

Handy Dandy Clone Machine

{2}, {T}: Create a 2/2 colorless Homunculus creature token. It must be represented by a unique hand and two fingers at all times, or it ceases to exist.

Enraged Killbot

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.)

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.

Summon the Pack

Open a sealed Magic booster pack, reveal the cards, and put all creature cards revealed this way onto the battlefield under your control. They're Zombies in addition to their other types. (Remove those cards from your deck before beginning a new game.)

Mary O'Kill

{1}{B/R}: Switch a Killbot or Mary O'Kill in your hand with one on the battlefield. (If a creature is tapped, the switched creature is tapped. The same is true for untapped, attacking, blocking, enchanted, equipped, and targeted. Any counters on a creature are on the switched creature instead.)

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.

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.