Is Monstrosity of the Lake legal in Standard, Modern, and Commander?

Monstrosity of the Lake is legal in: Legacy, Vintage, Commander.

Monstrosity of the Lake

Q: What type of card is Monstrosity of the Lake?

Monstrosity of the Lake is a Legendary Creature — Kraken. Its oracle text reads: "When Monstrosity of the Lake enters, you may pay {5}. If you do, tap all creatures your opponents control, then put a stun counter on each of those creatures. (If a permanent with a stun counter would become untapped, remove one from it instead.) Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)"

Legendary Creature — Kraken

When Monstrosity of the Lake enters, you may pay . If you do, tap all creatures your opponents control, then put a stun counter on each of those creatures. (If a permanent with a stun counter would become untapped, remove one from it instead.)