Purple felt-tip pen

Somewhere in my house is the other half of a purple felt-tip pen. Nothing as simple as I have the cap and not the body, or vice versa. No, this one was broken in half. I am looking for a suspect with purple teeth or purple paws. He should be considered armed and colorful.

I know exactly where to find the other half of my broken purple felt-tip pen, if I think about it a little bit. Where would be the worst possible place to have a massive purple stain? Start looking there.