Proof that I am working on the Yoruichi pic. Will move this to scraps later.
Often one relates a donkey tf with the bray, but sometimes I like to imagine what happens when the character resists said urge to haw. My guess is that they will simply grind their growing teeth, focusing way too much on not braying that they build so much pressure, making the facial changes come up more drastic and faster, up to the point their breathing becomes loud snorts and grunts.

... yeah, sometimes I overthink this kind of thHEEngs...