Spirit, you already know I think you're good. Your execution is always pretty great.
I didn't see the Earth reference right away either, thought once I did, it still wasn't striking to me (especially since the cookie is so flat). Forgetting that, the cookie's eyes have that glazed/sterile/lifeless look to them that I'm not a big fan of. And the two of them look almost like they have nothing to do with one another except for the evidence of floating crumbs.
The fur looks great, and you always pick nicely contrasting colors, but I can't get over that they both just look plastered on the shirt separately. Maybe if the cookie was slightly tilted? Or perhaps if cookie monster was actually munching feverishly on him? As it is though, it falls flat to me.