Thought Harvester [Oath of the Gatewatch] Gnome put a rust counter on

put a rust counter on each artifact target opponent controls

Of course they do

You may cast Marang River Prowler from your graveyard as long as you control a black or green permanent

It has "{R}: This creature gets +1/+0 until end of turn

Set: Scars of Mirrodin Type: Artifact Creature — Myr Rarity: Common Cost: {2} {T}: Add {B}

Thought Harvester [Oath of the Gatewatch] Gnome put a rust counter onSet: Oath of the Gatewatch Type: Creature Eldrazi Drone Rarity: Uncommon Cost: {3}{U} Devoid (This card has no color.) Flying Whenever you cast a colorless spell, target opponent exiles the top card of their library. "I never thought I'd miss the gomazoa." Trinda, Hada spy patrol