Dub is a common Enchantment — Aura card from Core Set 2021 (M21), collector number 16. Current market price: $0.19 (foil $0.27), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.)