Is Felidar Guardian legal in Standard, Modern, and Commander?

Felidar Guardian is legal in: Modern, Legacy, Vintage, Commander. It is banned in: Pioneer.

Felidar Guardian

Q: What type of card is Felidar Guardian?

Felidar Guardian is a Creature — Cat Beast. Its oracle text reads: "When this creature enters, you may exile another target permanent you control, then return that card to the battlefield under its owner's control. *The loyalty of a felidar is hard won but worth the effort.* Power/Toughness: 1/4"