Is Return to the Sewers legal in Standard, Modern, and Commander?

Return to the Sewers is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Return to the Sewers

Q: What type of card is Return to the Sewers?

Return to the Sewers is an Instant. Its oracle text reads: "Target creature's owner puts it on their choice of the top or bottom of their library. You create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")"

Instant

Target creature's owner puts it on their choice of the top or bottom of their library. You create a Mutagen token. (It's an artifact with ", , Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")