“ Actually a real-world fungus, just heard about it. A fungus that tastes well and all, no ill effects. UNLESS you consume some beverage, even 3 (three) days after eating it. Then you become really sick, pains, vomiting, all the fancy stuff. Was really used to cure alcoholism. May be a joke or to make sure the heroes spend their time focused on the mission.”
“ The forests, the swamps, the lands lost to wilderness, fang, and willow. These lands are home to the creatures of wiing, tooth and claw. Some far more capable of fending off the hominids, others still, are less fortunate, falling prey to spears, arrows, and dogs. As the hominids encroach upon the sacred woodlands and miry bogs there are times that the thorns and vines are animated by the spirit of the land in order to fight. In this way the mysterious guardians are formed. In the shapes of wolves, bears, and many other greater and more terrible beasts, each with eyes of glowing emerald. Fiercely defending creatures of burrow and glade.”
“ If you want to add a 'supernatural' touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.”