Is Karumonix, the Rat King legal in Standard, Modern, and Commander?

Karumonix, the Rat King is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Karumonix, the Rat King

Q: What type of card is Karumonix, the Rat King?

Karumonix, the Rat King is a Legendary Creature — Phyrexian Rat. Its oracle text reads: "Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) Other Rats you control have toxic 1. When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order."

Legendary Creature — Phyrexian Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Other Rats you control have toxic 1.

When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Set Phyrexia: All Will Be One

Rarity Rare

Mana Value 3

Artist Helge C. Balzer

Collector # 98

Scryfall Gatherer