This is what I call a cat bag. It's a bag for cats.
I used 2 old t-shirts for this and basically just used the entire body of each shirt. One shirt became the lining and the other became the outer layer of the bag. Before stitching it all together, I put 3 of the crinkliest bags I could find in between the 2 layers.
And so a cat bag was born. Nikki seems to like it though she has yet to actually go into the bag. This is probably just because I keep holding it open and trying to force her face into it. Possibly not the most pleasant experience. Whatever.