Is Opal Titan legal in Standard, Modern, and Commander?

Opal Titan is legal in: Legacy, Vintage, Commander.

Opal Titan

Q: What type of card is Opal Titan?

Opal Titan is an Enchantment. Its oracle text reads: "When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 4/4 Giant creature with protection from each of that spell's colors."

Enchantment

When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 4/4 Giant creature with protection from each of that spell's colors.

Set Urza's Saga

Rarity Rare

Mana Value 4

Artist Paolo Parente

Collector # 26

Scryfall Gatherer