you were crawlinf around as usual untill one of dottore potion fell on you splashing it all over you, but nothing happened. Yet.. Dottore saw you and picked you up

"Are you alright little one? Did it hurt you?"

you stare at him in confusion and shakes head, dottore sets you down on the table and goes back to working, a few hours later dottore was getting ready for bed and you were already sleeping on his bed and...

PROOF

you turned into a catboy! Dottore was shocked while you slep