http://fdiland2k23drdjqmxgmnjmzb47s3ildy5wyh5t4gk2tgjo3yfdffyyd.onion/kemono/thread/2.html
Especially with how in the manhua they're shown to be able to freely go in and out of each other's gullets, the Bixie impregnation theory weirdly checks out.
By the way, apparently multiple kinds of Pixiu are distinguished by their habitat. Pixiu is the default, earthly kind, 77th is what's called a Piyao, and apparently there is also a vaporeon breed with scales and webbed feet.