Is Vexing Radgull legal in Standard, Modern, and Commander?

Vexing Radgull is legal in: Legacy, Vintage, Commander.

Vexing Radgull

Q: What type of card is Vexing Radgull?

Vexing Radgull is a Creature — Bird Mutant. Its oracle text reads: "Flying Whenever this creature deals combat damage to a player, that player gets two rad counters if they don't have any rad counters. Otherwise, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.) *Fighting one is a terrible experience.* Power/Toughness: 1/2"

Creature — Bird Mutant

Flying

Whenever this creature deals combat damage to a player, that player gets two rad counters if they don't have any rad counters. Otherwise, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

*Fighting one is a terrible experience.*

Power/Toughness: 1/2

Set Fallout

Rarity Uncommon

Mana Value 2

Artist Josu Solano

Collector # 41

Scryfall