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.

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.)

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.

Voracious Vacuum

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

Inflation Station

Whenever you crank Inflation Station, target creature gets +3/+3 until end of turn.

Mountain

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.

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.

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.

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.

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.)

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.)

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.

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.

Enraged Killbot

Eager Beaver

When this creature enters, you may untap target permanent.

Sap Sucker

Whenever you crank Sap Sucker, add {G}. Until end of turn, you don't lose this mana as steps and phases end.

Krark's Other Thumb

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

Boomflinger

Whenever you crank Boomflinger, roll two six-sided dice. Boomflinger deals damage to target player or planeswalker equal to the difference between those results.

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.

Insufferable Syphon

Whenever you crank Insufferable Syphon, target player discards a card.

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.)

Auto-Key

Whenever you crank Auto-Key, until end of turn, target creature becomes an artifact in addition to its other types and gains "{T}: You gain 3 life."

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.

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.)

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.

Forest

Box of Free-Range Goblins

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

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.

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.