Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

Curious Forager

When Curious Forager enters, you may forage. When you do, return target permanent card from your graveyard to your hand. (To forage, exile three cards from your graveyard or sacrifice a Food.)

Earthcraft

Tap an untapped creature you control: Untap target basic land.

Living Lands

All Forests are 1/1 creatures that are still lands.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Cauldron Familiar

When Cauldron Familiar enters, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return Cauldron Familiar from your graveyard to the battlefield.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Kormus Bell

All Swamps are 1/1 black creatures that are still lands.

Living Plane

All lands are 1/1 creatures that are still lands.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Exploration

You may play an additional land on each of your turns.

Collector Ouphe

Activated abilities of artifacts can't be activated.

Experimental Confectioner

When Experimental Confectioner enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Whenever you sacrifice a Food, create a 1/1 black Rat creature token with "This creature can't block."

Ygra, Eater of All

Ward—Sacrifice a Food.
Other creatures are Food artifacts in addition to their other types and have "{2}, {T}, Sacrifice this permanent: You gain 3 life."
Whenever a Food is put into a graveyard from the battlefield, put two +1/+1 counters on Ygra, Eater of All.

Null Rod

Genesis Chamber

Whenever a nontoken creature enters, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Camellia, the Seedmiser

Menace
Other Squirrels you control have menace.
Whenever you sacrifice one or more Foods, create a 1/1 green Squirrel creature token.
{2}, Forage: Put a +1/+1 counter on each other Squirrel you control. (To forage, exile three cards from your graveyard or sacrifice a Food.)

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Utopia Sprawl

Enchant Forest
As Utopia Sprawl enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

Kill Switch

{2}, {T}: Tap all other artifacts. They don't untap during their controllers' untap steps for as long as Kill Switch remains tapped.