Is Llanowar Sentinel legal in Standard, Modern, and Commander?

Llanowar Sentinel is legal in: Modern, Legacy, Vintage, Commander, Pauper.

Llanowar Sentinel

Q: What type of card is Llanowar Sentinel?

Llanowar Sentinel is a Creature — Elf. Its oracle text reads: "When this creature enters, you may pay {1}{G}. If you do, search your library for a card named Llanowar Sentinel, put that card onto the battlefield, then shuffle. *"The forest has as many eyes as leaves." —Mirri of the *Weatherlight** Power/Toughness: 2/3"

Creature — Elf

When this creature enters, you may pay . If you do, search your library for a card named Llanowar Sentinel, put that card onto the battlefield, then shuffle.