What The Heck Is This Thing In My Office?

So I briefly went up stairs to grab a drink. Upon my return however I noticed something in the corner of my eye and quickly turned my head and saw some kind of creature wearing my hat and standing on my shelving where my Gundam / Toys sit.

Before it noticed me I quickly snapped a picture on my trusty Android phone so that my wife would believe me when I said I found a creature in my office. The proof is in the pudding so they say, so what the heck this is thing? And why is it wearing my hat? And would I even want my hat back now?

The mind boggles.