Is Tekuthal, Inquiry Dominus legal in Standard, Modern, and Commander?

Tekuthal, Inquiry Dominus is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Tekuthal, Inquiry Dominus?

Tekuthal, Inquiry Dominus is a Legendary Creature — Phyrexian Horror. Its oracle text reads: "Flying If you would proliferate, proliferate twice instead. {1}{U/P}{U/P}, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal. ({U/P} can be paid with either {U} or 2 life.) Power/Toughness: 3/5"

Tekuthal, Inquiry Dominus

Legendary Creature — Phyrexian Horror

Flying

If you would proliferate, proliferate twice instead.

, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal. ( can be paid with either or 2 life.)