I was listening to Rakan's interactions and I got to wondering. It would make sense given that Wukong is from Ionia.
It's also interesting to note that Rengar is Vastaya, Swain has Vastaya blood (I'm guessing an experiment/transfusion), and Udyr's power comes from Vastaya. We also know Ahri is Vastaya and I'm gonna guess that Nidalee is too.
Wukong probably is Vastaya too.
Wukong is Vastaya.
Udyr is not Vastayan and has no Vastayan blood, btw. It's just his martial arts.
Why are people constantly saying Udyr?
Udyr is a martial artist who does different combat styles. Tiger Style, Bear Style, Turtle Style, and Phoenix Style. Those are fighting styles. He doesn't actually change into any animals. He is not a shapeshifter.
I'm not sure. In the old lore, both wukong and nidalee got their power from environmental stimuli. The jung nid was raised in altered her body structure and I forget what exactly Wu's lore was, but it was similar.
He is not an animal, he is rock creature like 
Vastaya are a phylum (not species) so it's probable.
Unconfirmed but yeah, probably.
If I'm right Wukong is fully a monkey with a mutation and his origin is from the Plague Jungles rather than Ionia. He was, I believed, taught Wuju by Master Yi. Same with Volibear. He is actually fully an animal, though champions like Alistar should be half human half cow since he is a Minotaur.
I havent listened to the vo spotlights yet, but if you have read lore, there is a pig shapeshifter that is several generations diluted. Nidalee is vastaya, just raised in jungle by animals.
Ahri i dont think is one though. She stole a human soul and/or body (dont remember which). Visually similar, but not born like them. I'm assuming vastaya are a number of true spieces that physically procreate and dont magically spawn or come into being
