Clockwork Dragon is a rare Artifact Creature — Dragon card from Mirrodin (MRD), collector number 155. Current market price: $0.48 (foil $22.05), TCGplayer market prices via Scryfall.
Flying This creature enters with six +1/+1 counters on it. Whenever this creature attacks or blocks, remove a +1/+1 counter from it at end of combat. {3}: Put a +1/+1 counter on this creature.