Is Grow Extra Arms legal in Standard, Modern, and Commander?

Grow Extra Arms is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Grow Extra Arms

Q: What type of card is Grow Extra Arms?

Grow Extra Arms is an Instant. Its oracle text reads: "This spell costs {1} less to cast if it targets a Spider. Target creature gets +4/+4 until end of turn. *"I created that potion to rob me of my spider-powers. I wanted it to change me forever. But not like this! NOT LIKE THIS!"*"