Cheapest priced copy (Jumpstart 2022): $0.35 at Card Kingdom, near mint, their price list as of .
Stinging Lionfish 
Enchantment Creature — Fish · 2/1 · Uncommon · Theros Beyond Death · #69
Whenever you cast your first spell during each opponent's turn, you may tap or untap target nonland permanent.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Jumpstart 2022 | 352 | Uncommon | $0.35 | — |
| Foundations Jumpstart | 367 | Uncommon | $0.35 | — |
| Theros Beyond Death | 69 | Uncommon | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 24 January 2020If you have more than one opponent, this ability can trigger once during each of those opponents' turns.
- 24 January 2020In a Two-Headed Giant game, this ability triggers no more than once during each opposing team's turn.
- 24 January 2020This ability triggers only on your very first spell during an opponent's turn, not the first spell after the card is on the battlefield. If you cast a spell before it's on the battlefield (including if you cast this card somehow during an opponent's turn), the ability won't trigger.
- 24 January 2020An ability that triggers when you cast a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.