Only ONE thing is truly certain in wassiecanon, and that is the forces that rendered wassie real were so powerful they shattered reality. Most people failed to notice this, but it does mean that anything and everything people want to believe and / or write and / or film and / or animate and / or puppeteer and / or believe is totally compatible with every other item of wassie lore. Even – indeed especially – if these facts contradict.
For example, saying that wassies are 6 feet tall with an insatiable hunger for cat food in no way invalidates them being able to sleep on the bottom level of a shoe rack while devouring soup. Thanks to there being an infinite number of dimensions this is all fine.