That is a very cute replica of your lusus!
COOPERI (also known as COOP) is a member of the STRYX family, rare lusii valued due to the unique properties of their FEATHERS. Her plush toy was hand-crafted by your good friend LAIVAN, who knew that you probably wouldn't want to sleep by yourself. She is far too big to fit into your tiny hive, so he made it for you.
He was definitely right in that it makes your sudden bouts of anxiety and tension a little easier to handle. It's not the same as having some actual sopor, but it is very good for hugging!