Is Mephidross Slime legal in Standard, Modern, and Commander?

Mephidross Slime is legal in: Historic.

Mephidross Slime

Q: What type of card is Mephidross Slime?

Mephidross Slime is a Creature — Phyrexian Ooze. Its oracle text reads: "Trample When Mephidross Slime dies, conjure a card named Mephidross Slime into your graveyard. Perpetually double the power and toughness of Mephidross Slime and that card, then shuffle them into their owner's library. Power/Toughness: 3/3"

Creature — Phyrexian Ooze

Trample

When Mephidross Slime dies, conjure a card named Mephidross Slime into your graveyard. Perpetually double the power and toughness of Mephidross Slime and that card, then shuffle them into their owner's library.

Power/Toughness: 3/3

Set Alchemy: Phyrexia

Rarity Uncommon

Mana Value 3

Artist Yeong-Hao Han

Collector # 25

Scryfall