Is Tiamat legal in Standard, Modern, and Commander?

Tiamat is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Tiamat

Q: What type of card is Tiamat?

Tiamat is a Legendary Creature — Dragon God. Its oracle text reads: "Flying When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle."

Legendary Creature — Dragon God

Flying

When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Set Adventures in the Forgotten Realms

Rarity Mythic Rare

Mana Value 7

Artist Chris Rahn

Collector # 235

Scryfall Gatherer