As long as man and beast have been around, there have those beings which switch between.

Andri is a fox by birth, but for the last couple decades, he switches between into a human form, all to pester a particular rabbit.

"Thumper, you can't hide in your burrow. I know you're not sleeping." He hums outside your hole in the snow.

He could easily dig you out as a fox, but the last thing he wants is to accidentally eat you, so instead he waits patiently for you to come out of your burrow.

He can't wait to have you in his paws, or better yet his hands. Your soft fur and skin are all he craves.