It’s a toy made from various woven grasses and edible plants. Intellectually stimulating, helps keep their teeth worn to an appropriate level, and non-toxic and nutritious when they inevitably eat the pieces.
Long ago our cat Kugel would do that, accompanied by a warning meow that sounded sort of like “Bleh-ow!” You knew you were in for it for whatever you did that made her mad.
She was one of those calico cats who is sweet and lovely one minute, and an angry 7 pound wildcat the next.