Is Three Dog, Galaxy News DJ legal in Standard, Modern, and Commander?

Three Dog, Galaxy News DJ is legal in: Legacy, Vintage, Commander.

Three Dog, Galaxy News DJ

Q: What type of card is Three Dog, Galaxy News DJ?

Three Dog, Galaxy News DJ is a Legendary Creature — Human Bard. Its oracle text reads: "Whenever you attack, you may pay {2} and sacrifice an Aura attached to Three Dog. When you sacrifice an Aura this way, for each other attacking creature you control, create a token that's a copy of that Aura attached to that creature."

Legendary Creature — Human Bard

Whenever you attack, you may pay and sacrifice an Aura attached to Three Dog. When you sacrifice an Aura this way, for each other attacking creature you control, create a token that's a copy of that Aura attached to that creature.