Is Brineborn Cutthroat legal in Standard, Modern, and Commander?

Brineborn Cutthroat is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Brineborn Cutthroat

Q: What type of card is Brineborn Cutthroat?

Brineborn Cutthroat is a Creature — Merfolk Pirate. Its oracle text reads: "Flash (You may cast this spell any time you could cast an instant.)Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature."

Creature — Merfolk Pirate

Flash (You may cast this spell any time you could cast an instant.)<br>Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Set Pioneer Masters

Rarity Uncommon

Artist Caio Monteiro