Is Optimistic Scavenger legal in Standard, Modern, and Commander?

Optimistic Scavenger is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Optimistic Scavenger

Q: What type of card is Optimistic Scavenger?

Optimistic Scavenger is a Creature — Human Scout. Its oracle text reads: "Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, put a +1/+1 counter on target creature. *"A void rod? Perfect! Now I'll be able to get the glitch reader working again."* Power/Toughness: 1/1"