Jackknight

Whenever another artifact you control enters, put a +1/+1 counter on Jackknight. If that artifact is a Contraption, Jackknight gains lifelink 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.

Plains

Knight of the Kitchen Sink

First strike, protection from odd collector numbers (Nothing with an odd collector number can block, target, deal damage to, or attach to this creature.)

Contraption Cannon

{2}, Sacrifice Contraption Cannon: It deals damage to any target equal to the number of Contraptions you control.

AWOL

Exile target attacking creature. Then remove it from the game. Then put it into the absolutely-removed-from-the-freaking-game-forever zone.

Oddly Uneven

Choose one —
• Destroy each creature with an odd number of words in its name. (Hyphenated words are one word.)
• Destroy each creature with an even number of words in its name.

Knight of the Widget

Vigilance
Knight of the Widget's power and toughness are each equal to the number of Order of the Widget watermarks among permanents you control.

Midlife Upgrade

As an additional cost to cast this spell, sacrifice X Contraptions.
Assemble X plus one Contraptions. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

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.)

First strike, protection from watermarks (Nothing with a watermark can block, target, deal damage to, or attach to this 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}

Syr Cadian, Knight Owl

Knightlifelink (Damage dealt by Knights you control also causes you to gain that much life.)
{W}: Syr Cadian, Knight Owl gains vigilance until end of turn. Activate only from sunrise to sunset.
{B}: Syr Cadian, Knight Owl gains flying until end of turn. Activate only from sunset to sunrise.

Aerial Toastmaster

Flying
{3}{W}, Sacrifice another artifact: Aerial Toastmaster assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Amateur Auteur

Sacrifice Amateur Auteur: Destroy target enchantment.

Riveting Rigger

When Riveting Rigger enters, you may sacrifice another artifact. If you do, put two +1/+1 counters on Riveting Rigger and it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Man of Measure

As long as you're shorter than an opponent, Man of Measure gets +0/+1 and has first strike.
As long as you're taller than an opponent, Man of Measure gets +1/+0.

First strike, protection from even collector numbers (Nothing with an even collector number can block, target, deal damage to, or attach to this creature.)

My First Tome

{1}, {T}: Say the flavor text on a card in your hand. Target opponent guesses that card's name. You may reveal that card. If you do and they guessed wrong, you draw a card.

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.

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.