Mountain

Plains

Iron Myr

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Suntouched Myr

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)

Forest

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Myr Adapter

Myr Adapter gets +1/+1 for each Equipment attached to it.

Skyscanner

Flying
When Skyscanner enters, draw a card.

Island

Urtet, Remnant of Memnarch

Whenever you cast a Myr spell, create a 1/1 colorless Myr artifact creature token.
At the beginning of combat on your turn, untap each Myr you control.
{W}{U}{B}{R}{G}, {T}: Put three +1/+1 counters on each Myr you control. Activate only during your turn.

Myr Quadropod

{3}: Switch Myr Quadropod's power and toughness until end of turn.

Swamp

Perilous Myr

When Perilous Myr dies, it deals 2 damage to any target.

Myr Moonvessel

Palladium Myr

Myr Landshaper

{T}: Target land becomes an artifact in addition to its other types until end of turn.

Copper Myr

Myr Sire

When Myr Sire dies, create a 1/1 colorless Phyrexian Myr artifact creature token.