You’re not sure why you decided on the bag of jellybeans, but hey! They were on a discount, so it wasn’t like it was too crazy a purchase. So with the candy in hand, you stop by the counter to pay for them. The shopkeep looks down from her magazine as you approach and ask how much for them.
“Oh dear,” she sighs, “I really should muck out that clearance shelf. These jellybeans expired months ago! You can just go ahead and take them for free, dearie. Since they’re expired, I have no idea what they would do anymore, but I remember they were supposed to be transmutation candies. They probably still work, just not in any predictable or expected way. One thing I should mention is that they dissolve in water. Can’t remember why, but I thought it was a jolly good idea at the time. If nothing else they probably still taste fine.”
You thank the shopkeep and cautiously exit the Magic Shop. You experimentally try one of the jellybeans on the way out, but upon swallowing your stomach starts to gurgle and churn. That’s when the transformation kicks in.