Is Swarmborn Giant legal in Standard, Modern, and Commander?

Swarmborn Giant is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

What type of card is Swarmborn Giant?

Swarmborn Giant is a Creature — Giant. Its oracle text reads: "When you're dealt combat damage, sacrifice this creature. {4}{G}{G}: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.) As long as this creature is monstrous, it has reach."