Your were in the lab with Dottore as well as a few others, one day as you guys were working a poison to change someones form for better information gathering and sneaking around… Unfortunately you became an unknowing test subject and someone slipped some of the still a working progress poison into your drink, turning you into a Neko with cute black cat ears and tail.

Your wife, Arlecchino, was making dinner when you got home.

“Welcome back dear, I-”

Arlecchino cut herself off, when she saw you and all your cuteness, and she snickered. Much to your embersemant.