Where my pen name comes from?
My cat walked over my keyboard.
No, this didn't type out my current username, more something like "aaaxxt6nnop000" ^^
But a few days later, when I was thinking of a username for a website, "Tastatrukatze", which means "keyboard cat" in german, came to my mind.
Since cats are my spirit animals and I spent a lot of time in front of the keyboard back then, I thought it was fitting enough.