Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Sol Ring

Hangarback Walker

Hangarback Walker enters with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

Triskelavus

Flying
Triskelavus enters with three +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Triskelavus: Create a 1/1 colorless Triskelavite artifact creature token with flying. It has "Sacrifice this creature: This creature deals 1 damage to any target."

Cloudpost

Cloudpost enters tapped.
{T}: Add {C} for each Locus on the battlefield.

Pentavus

Pentavus enters with five +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Pentavus: Create a 1/1 colorless Pentavite artifact creature token with flying.
{1}, Sacrifice a Pentavite: Put a +1/+1 counter on Pentavus.

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Throne of Geth

{T}, Sacrifice an artifact: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Glimmerpost

When Glimmerpost enters, you gain 1 life for each Locus on the battlefield.
{T}: Add {C}.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Kuldotha Forgemaster

{T}, Sacrifice three artifacts: Search your library for an artifact card, put it onto the battlefield, then shuffle.

Krark-Clan Ironworks

Scrapyard Recombiner

Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
{T}, Sacrifice an artifact: Search your library for a Construct card, reveal it, put it into your hand, then shuffle.

Tetravus

Flying
Tetravus enters with three +1/+1 counters on it.
At the beginning of your upkeep, you may remove any number of +1/+1 counters from Tetravus. If you do, create that many 1/1 colorless Tetravite artifact creature tokens. They each have flying and "This creature can't be enchanted."
At the beginning of your upkeep, you may exile any number of tokens created with Tetravus. If you do, put that many +1/+1 counters on Tetravus.

Scrap Trawler

Whenever Scrap Trawler or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.