CONTENT WARNING: This video uses some really gnarly parasite imagery from 1:30-2:03.
The Thing (2011) gets a lot of fuss for the supposed badness of its CGI. "Practical effects are better!" scream the masses, "the CG ruined it!" Practical effects are nice, but I don't think that's what makes the 1982 version of The Thing a better movie.
Sources:
Nussbaum, Martha C. Hiding from Humanity: Disgust, Shame, and the Law." Princeton University Press, 2004.
Roger Ebert's review of The Thing: https://www.rogerebert.com/reviews/the-thing-1982
David Denby's review of The Thing: https://books.google.com/books?id=0-cCAAAAMBAJ&pg=PA53#v=onepage&q&f=false
For a great book on parasites check out Parasite Rex by Carl Zimmer.