Lightning Coils is a rare Artifact card from Mirrodin (MRD), collector number 198. Current market price: $0.66 (foil $3.69), TCGplayer market prices via Scryfall.
Whenever a nontoken creature you control dies, put a charge counter on this artifact. At the beginning of your upkeep, if this artifact has five or more charge counters on it, remove all of them from it and create that many 3/1 red Elemental creature tokens with haste. Exile them at the beginning of the next end step.