Thunderdrum Soloist is a uncommon Creature — Dwarf Bard card from Secrets of Strixhaven (SOS), collector number 134. Current market price: $0.29 (foil $0.33), TCGplayer market prices via Scryfall.
Reach Opus — Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent. If five or more mana was spent to cast that spell, this creature deals 3 damage to each opponent instead.