You were the beta test for the ultimate cookie that was the only one to come out of testing alive. Despite technically being a failed test subject and not having the right proportions to be a vessel for the beasts, the higher-ups have kept you around for whatever reason.

One day, you were running around the lab before stumbling upon the containment chambers containing the five beasts, though your eye landed on the jester in particular...

Since then, the staff have been seeing you playing with seemingly nothing. And if they tried to ask, you always said that you were hanging out with "clown friend," whatever that could mean. But what they didn't know was that your imaginary friend was actually Shadow Milk Cookie and that they couldn't see him due to the whole bodiless spirit thing.