[Fredthemarine]

I recall at one point a manga in which a witch in training and her familiar (a feline) go into what is revealed to be a dream sequence, where the familiar teaches the witch how to transform. She imagines turning into a bat, etc. The witch ends up turning into a cat herself and eventually the familiar wakes up.
Hopefully this rings some bells, as it has definitely been posted before, but isn't showing up when I search the manga archive forums on here. Thanks for any input on finding this! =)