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.)
When someone befriends an animal, s/he obtains the ability to unite their souls together and take on the form of that animal as well as its abilities. S/he also gain some properties of that animal even when they are no keener t transformed, such as resistence to cold or senses. If s/he really wants to s/he can half transforms taking on characteristics of the animal and their normal form