Picking up on an earlier post, here is some more art by Muzski, mangling the works of Hergé and Lovecraft in some trans-dimensional, non-euclidean way and producing something hardly imaginable:
I guess this scenario would actually make a fun scenario. The Yithians are not evil, they are just scientists. With a little bit of tweaking they could easily take the role of good guys or hidden supporters in the background.
Anyway, I think they pose far less of a threat to Tintin than some of the other foe he faced in his career. The specimen pictured above is propably the librarian wanting to give the poor los human a hand (or pincer, in this case).
Nothing to worry about.