You control no more than two additional creatures.
Steps
Activate Krark-Clan Ironworks by sacrificing Sword of the Meek, adding ({C} magic symbol) ({C} magic symbol) .
Skittering Precursor triggers, creating a 0/1 Eldrazi Spawn creature token.
When the Eldrazi Spawn enters the battlefield as a 1/1 due to Jetmir, Sword of the Meek triggers, returning Sword of the Meek from your graveyard to the battlefield attached to the Eldrazi Spawn.
Activate the Eldrazi Spawn by sacrificing it, adding ({C} magic symbol) .