Psilocybe Dragon

The Psilocybe Dragon is one of the more bizarre mutants roaming the post-P-Day landscape. It's a pretty big beast, and it can debuff the heck out of anyone that gets near it. It will also probably eat you.

See, a feral Psilocybe Dragon has one major concern - reproduction. For most ferals, that would mean sex, but this mutant reproduces in a more... visceral manner. Specifically, its sole object in combat is to seize an opponent in its jaws and swallow them whole. To observers this appears to be a feeding behavior, but the swallowed victim is not sent to the Psilocybe Dragon's actual stomach. Instead they go to a different organ, one situated a bit further down in the gut. Zephyr scientists have dubbed this organ the inoculation pouch, but agents in the field are liable to refer to it as the 'second stomach'. In any event, swallowed victims are held in the pouch until the Psilocybe Dragon's nanites are able to infect the victim thoroughly. Once the victim has been infected, the Dragon will take itself to a safe place and regurgitate the newly infected victim. Unless treated, the victim will soon develop into a Psilocybe Dragon themselves.

TLDR? It's a dragon made out of shrooms. And it will eat you, then puke you up and leave you in a puddle of slime and spores.