Is Wildfire Cerberus legal in Standard, Modern, and Commander?

Wildfire Cerberus is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

Wildfire Cerberus

Q: What type of card is Wildfire Cerberus?

Wildfire Cerberus is a Creature — Dog. Its oracle text reads: "{5}{R}{R}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.) When this creature becomes monstrous, it deals 2 damage to each opponent and each creature they control. Power/Toughness: 4/3"