Cybermat

Artifact Creature — Robot (2/1)

Skulk (This creature can't be blocked by creatures with greater power.)
Whenever Cybermat attacks and isn't blocked, it gets +X/+0 until end of turn, where X is the number of attacking artifact creatures.

Cyclopean Snare

Artifact

, : Tap target creature, then return Cyclopean Snare to its owner's hand.

Dagger of the Worthy

Artifact — Equipment

Equipped creature gets +2/+0 and has afflict 1. (Whenever it becomes blocked, defending player loses 1 life.)
Equip (: Attach to target creature you control. Equip only as a sorcery.)

Damping Sphere

Artifact

If a land is tapped for two or more mana, it produces instead of any other type and amount.
Each spell a player casts costs more to cast for each other spell that player has cast this turn.

Darksteel Brute

Artifact

Indestructible (Damage and effects that say "destroy" don't destroy this artifact.)
: Darksteel Brute becomes a 2/2 Beast artifact creature until end of turn.

Darksteel Garrison

Artifact — Fortification

Fortified land has indestructible.
Whenever fortified land becomes tapped, target creature gets +1/+1 until end of turn.
Fortify (: Attach to target land you control. Fortify only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the land leaves.)

Darksteel Pendant

Artifact

Indestructible (Effects that say "destroy" don't destroy this artifact.)
, : Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Decoction Module

Artifact

Whenever a creature enters the battlefield under your control, you get (an energy counter).
, : Return target creature you control to its owner's hand.

Delighted Killbot

Artifact Creature — Killbot (2/1)

Demon's Horn

Artifact

Whenever a player casts a black spell, you may gain 1 life.

Despondent Killbot

Artifact Creature — Killbot (2/1)

Diamond Mare

Artifact Creature — Horse (1/3)

As Diamond Mare enters the battlefield, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Digsite Conservator

Artifact Creature — Gnome (2/1)

Sacrifice Digsite Conservator: Exile up to four target cards from a single graveyard. Activate only as a sorcery.
When Digsite Conservator dies, you may pay . If you do, discover 4. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Distorting Lens

Artifact

: Target permanent becomes the color of your choice until end of turn.

Dolmen Gate

Artifact

Prevent all combat damage that would be dealt to attacking creatures you control.

Doubling Cube

Artifact

, : Double the amount of each type of unspent mana you have.

Dragon's Claw

Artifact

Whenever a player casts a red spell, you may gain 1 life.

Dream Chisel

Artifact

Face-down creature spells you cast cost less to cast.

Dream-Thief's Bandana

Artifact — Equipment

Whenever equipped creature deals combat damage to a player, look at the top card of their library, then exile it face down. For as long as it remains exiled, you may play it, and mana of any type can be spent to cast that spell.
Equip

Dredging Claw

Artifact — Equipment

Equipped creature gets +1/+0 and has menace. (It can't be blocked except by two or more creatures.)
Whenever a creature enters the battlefield from your graveyard, you may attach Dredging Claw to it.
Equip (: Attach to target creature you control. Equip only as a sorcery.)