Like every generation of Pokémon, this one has Legendary Pokémon. These particular and powerful Pokémon are, most often, grouped into Trios and generally associated with a myth concerning the creation or organization of the world.
Also wanting to create a trio of Legendaries, I racked my brains to find a logical theme with myths or an aspect of our reality… after several attempts at a trio, I settled on the theme of Sounds!
The third Legendary is HUSHOOT, representing silence (therefore the total absence of sound, even parasitic).
Its Design borrows heavily from Owls, but in particular the Barn Owl. Her Norse mythological design is not particularly evocative, but it is inspired by a non-mythological and more aestheticized version of the goddess of death: Hel (in particular the version of the Marvel comics)
Besides her horned owl head, the rest of her body is ghostly in appearance. This aspect is obviously intentional, Ghosts and Owls being known to be silent beings, it seemed to me to be a perfect inspiration to represent Silence (and therefore no Tuning Fork)
Her Shiny is rather simple, her body of very little saturated colors, changes into a bluish version, a little more saturated. But normally, the Shiny of a legendary is not really visible, because of the mechanics of the Shiny-Lock.