So we didn't do any research on whether someone already went ahead and wrote this crossover fanfic, but I'd bet a lot of money that it's already been done because, you know, the internet. We may as well tack on a Rule 35 in addition to Rule 34: if something exists, there's a fanfic about it.
I'm forgetful as to how this comic came to be conceptually, but things fell into place. Almost too well. Thankfully, with a comic like this, backgrounds were the last thing on my mind.