Do we know for a fact this is a Legendary?
>>27656637
Yes.
>>27656637
No.
>>27656637
The islanders call it and treat it like deity and it has a very unique name.
I think it's safe to infer that they are. My theory is that tapu koko is going to be fast and defensive, as it seems like it (and possibly the others) is being made with doubles support in mind, considering all we know about it is that it has a terrain move as an ability and its signature move is a fairy-type super fang. Unless nature's madness is just another forgotten signature move, I can see these things having not much actual attacking power but rather relying on support roles and dealing chip damage like nature's madness.
>>27656637
The official site has given it a 2x2 big square on the Pokémon list, which only Solgaleo, Lunala and Magearna otherwise have. So that's a yes.
It's not listed as a legendary pokemon on the official site, but it seems like it's being treated like one
We don't know for sure, but judging by its cluttered, hectic, over-the-top design it totally is.
>>27656637
Maybe
>>27656637
Yes, no, yes, no, yes, no. I'm making a decision that is so hard!!!
>>27656637
It's likely a legendary in the sense that it's an unbreedable one-off mon. its general presence in the world (it appears after a bazillion years/no one has seen one in forever/it's hiding in that cave, we visit it often so we know it lives there/it's a roaming) is unknown