Insubordination is a common Enchantment — Aura card from Mercadian Masques (MMQ), collector number 141. Current market price: $0.08 (foil $1.17), TCGplayer market prices via Scryfall.
Enchant creature At the beginning of the end step of enchanted creature's controller, this Aura deals 2 damage to that player unless that creature attacked this turn.