Science fiction author: "I have created this extremely alien alien."
Biologists: "We have an insect that does that."
I was thinking Xenomorph (from Alien series), but I am sure there are insects that live inside other organisms in a similar way, not sure if any exit their host and kill their host in the process, Probably, then again that set up may have been the inspiration for the Xenomorph in the first place.
The parasitoid wasp inspiration for "Alien" was obvious.
It was also apparently inspired by writer Dan O'Bannon's experience with Crohn's disease.
@michael_w_busch @zleap The first one I considered obvious. The second one I didn't know, but certainly understandable. Crohn's and Ulcerative Colitis are two of the most miserable experiences the disregulated immune system can inflict on a human being. Something I can only wish on the people I deeply hate.
O'Bannon was also inspired by Crohn's in some of his other work: https://www.latimes.com/local/obituaries/la-me-dan-obannon19-2009dec19-story.html .
Thanks for this, I have just looked it up https://en.wikipedia.org/wiki/Parasitoid_wasp.
@zleap @michael_w_busch Parasitoids. There are lots of wasps that do that to spiders and other insects.