Is Scuttlegator legal in Standard, Modern, and Commander?

Scuttlegator is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Scuttlegator

Q: What type of card is Scuttlegator?

Scuttlegator is a Creature — Crab Turtle Crocodile. Its oracle text reads: "Defender {6}{G/U}{G/U}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.) As long as this creature has a +1/+1 counter on it, it can attack as though it didn't have defender."