Work a Double

Assemble two Contraptions. (Put the top card of your Contraption deck face up onto one of your sprockets. Then repeat this process.)

Labro Bot

When this creature enters, return target host card or card with augment from your graveyard to your hand.

Just Desserts

Just Desserts deals π damage to target creature. (π is the ratio of a circle's circumference to its diameter. (It's a smidgen more than 3.))

Watermarket

{T}: Add {C}{C}. Spend this mana only to cast spells with watermarks.

Goblin Haberdasher

Menace (This creature can't be blocked except by two or more creatures.)
Other creatures you control wearing hats in their art have menace.

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}

Steamflogger Temp

{6}, {T}: Steamflogger Temp assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

First Pick

Destroy target artifact or enchantment. Assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Cogmentor

Flying
{4}: Reassemble target Contraption you control. (Move it onto another one of your sprockets.)

Hydradoodle

As Hydradoodle enters, roll X six-sided dice. Hydradoodle enters with a number of +1/+1 counters on it equal to the total of those results.
Reach, trample

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.

Garbage Elemental

When Garbage Elemental enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Earl of Squirrel

Squirrellink (Damage dealt by this creature also causes you to create that many 1/1 green Squirrel creature tokens.)
Creature tokens you control are Squirrels in addition to their other creature types.
Other Squirrels you control get +1/+1.

Willing Test Subject

Reach
Whenever you roll a 4 or higher on a die, put a +1/+1 counter on Willing Test Subject.
{6}: Roll a six-sided die.

Party Crasher

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

Forest

Steam-Powered

{5}:
Augment {4} ({4}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Selfie Preservation

Search your library for a basic land card and reveal it. If there's a tree in its art, put it onto the battlefield tapped. Otherwise, put it into your hand. Then shuffle.

Druid of the Sacred Beaker

{T}: Add {G} for each Crossbreed Labs watermark among permanents you control.

Krark's Other Thumb

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

Half-Squirrel, Half-

Whenever a nontoken creature enters,
Augment {G} ({G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Feisty Stegosaurus

When this creature enters, roll a six-sided die. This creature deals damage equal to the result to target creature an opponent controls.

Clever Combo

Search your library for a host card or a card with augment, reveal it, put it into your hand, then shuffle.

Cramped Bunker

At the beginning of each opponent's upkeep, that player moves a permanent they control to touch Cramped Bunker and no other permanents. If the player can't, destroy each permanent they control that isn't touching Cramped Bunker, then sacrifice it.

Everythingamajig

{1}: Flip a coin. If you win the flip, add {C}{C}. Activate only as an instant.
{3}, {T}: Target player discards a card. Activate only during your turn.
{X}: Everythingamajig becomes an X/X Construct artifact creature until end of turn.

Gnome-Made Engine

When this creature enters, create a 1/1 colorless Gnome artifact creature token.

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.

Serpentine

Landfall — Whenever a land you control enters,
Augment {2}{G} ({2}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Secret Base

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell that shares a watermark with Secret Base.

Ground Pounder

{3}{G}: Roll a six-sided die. Ground Pounder gets +X/+X until end of turn, where X is the result.
Whenever you roll a 5 or higher on a die, Ground Pounder gains trample until end of turn.

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.

Box of Free-Range Goblins

Roll a six-sided die. Create a number of 1/1 red Goblin creature tokens equal to the result.

Mountain

Clock of DOOOOOOOOOOOOM!

{4}, {T}: Move the CRANK! counter to your Contraption deck's next sprocket and crank any number of that sprocket's Contraptions.

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.

Angelic Rocket

Flying
When this creature enters, you may destroy target nonland permanent.

As Luck Would Have It

Hexproof
Whenever you roll a die, put a number of luck counters on As Luck Would Have It equal to the result. Then if there are 100 or more luck counters on As Luck Would Have It, you win the game. (Count both rolls if you reroll a die.)

Three-Headed Goblin

Triple strike (This creature deals first-strike, regular, and last-strike combat damage.)

Wild Crocodile

When this creature enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Ineffable Blessing

As Ineffable Blessing enters, choose white-bordered or silver-bordered.
Whenever a creature you control with the chosen border enters, draw a card.

Infinity Elemental

Monkey-

Whenever a nontoken creature you control dies,
Augment {2}{G} ({2}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Eager Beaver

When this creature enters, you may untap target permanent.

Voracious Vacuum

When this creature enters, put a +1/+1 counter on target creature.

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.

Ol' Buzzbark

When Ol' Buzzbark enters, roll X six-sided dice onto the battlefield from a height of at least X inches. For each die, put a number of +1/+1 counters equal to the result on each creature you control that die is touching. For each die, Ol' Buzzbark deals damage equal to the result to each creature an opponent controls that die is touching.

Hammerfest Boomtacular

Whenever you cast a spell with a Goblin Explosioneers watermark, Hammerfest Boomtacular deals 2 damage to any target.

Half-Orc, Half-

Trample
At the beginning of each end step, if an opponent was dealt damage this turn,
Augment {1}{R}{R} ({1}{R}{R}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

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.

Mother Kangaroo

When this creature enters, roll a six-sided die. Put a number of +1/+1 counters on this creature equal to the result.

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.

Wrench-Rigger

When Wrench-Rigger enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Multi-Headed

At the beginning of each end step, if you rolled a die this turn,
Augment {4}{G} ({4}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Bumbling Pangolin

When this creature enters, you may destroy target artifact.

Common Iguana

When this creature enters, you may discard a card. If you do, draw a card.

Slaying Mantis

Just a second (As long as this spell is on the stack, players can't move permanents.)
Slaying Mantis enters by being thrown from a distance of at least three feet.
When Slaying Mantis enters, it fights each creature an opponent controls that it touched as it entered.

Stamp of Approval

As Stamp of Approval enters, choose a watermark.
Creatures you control with the chosen watermark get +1/+1.

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.

Joyride Rigger

When Joyride Rigger enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Chittering Doom

Whenever you roll a 4 or higher on a die, create a 1/1 green Squirrel creature token.

Steamflogger Boss

Other Riggers you control get +1/+0 and have haste.
If a Rigger you control would assemble a Contraption, it assembles two Contraptions instead.

Steamflogger of the Month

When Steamflogger of the Month enters, it assembles a Contraption for each Contraption you control. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

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.

Robo-

At the beginning of each end step, if an artifact entered the battlefield under your control this turn,
Augment {2} ({2}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Hammer Jammer

As Hammer Jammer enters, roll a six-sided die. Hammer Jammer enters with a number of +1/+1 counters on it equal to the result.
Whenever you roll a die, remove all +1/+1 counters from Hammer Jammer, then put a number of +1/+1 counters on it equal to the result.

Steel Squirrel

Whenever you roll a 5 or higher on a die, Steel Squirrel gets +X/+X until end of turn, where X is the result.
{6}: Roll a six-sided die.

Steamfloggery

Roll a six-sided die. Assemble a number of Contraptions equal to the result. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

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.