Talk about the card Thopter Assembly from Mirrodin Beseiged

Thopter Assembly 6
Artifact Creature - Thopter (Rare)
Flying
At the beginning of your upkeep, if you control no Thopters other than Thopter Assembly, return Thopter Assembly to its owner's hand and put 5 1/1 colorless Thopter artifact creature tokens with flying onto the battlefield.
5/5