“ In one region of a forest, all of the trees are identical, down to the leaves and the twigs. If the PCs carve something into one of the trees, it could mystically propigate until it covered all of the trees, or could vanish since it was not carved into the one true tree.”
“ The PCs are exploring the catacombs beneath a Colosseum-in-Rome type of structure, when they come across a foul-smelling, stagnant, ankle-deep with algae, public mass latrine. Countless urinals of marble, line this rather large chamber equally crafted of marble. Whatever system of plumbing once worked here, has not in many years. Old graffiti lines the stained,dirty walls, prominently bolded are such intellectual poetic musings as, 'Urine For It Now', 'I Pee Therefore It Comes' and 'Now Urine Trouble'.
A few moments after the PCs get to take in this unpleasant location, they hear the low rumbling of ancient plumbing and rather large Urine Elemental rises like a great, wet, wave of filth to attack them. The creature reeks and exudes noxious debilitating fumes, while its liquid strikes burn flesh like acid.”
“ You find a patch of edible funghi. They taste well and all, no ill effects. UNLESS you consume some beverage, even 3 (three) days after eating it. Then you become really sick with pains, vomiting, all the fancy stuff. As a gift or good meal, it could be a cruel joke or to make sure the heroes spend their time focused on the mission. And the fine soup you had in the inn yesterday could have some in.
(Inspired through a real-world fungus. Was really used to cure alcoholism.)”