Mr. Tea
Let's Talk About Ceps
Interesting that you're brought up the xenomorph, because strictly speaking it's not a parasite, but a parasitoid.It's interesting about parasites and psychopaths
Like viruses they can't be too deadly or they destroy their hosts
The former doesn't kill its host as a normal part of its life cycle (e.g. fleas, tapeworms, etc.) while the latter does (like wasps that lay eggs in caterpillars).