Jack-in-the-Box

Origin
The exact origins of this toy are unknown, but, based on its main effect, it is theorized that it may have been used as some sort of therapy tool for treating coulrophobia.

Effects
When the crank is wound, the toy plays "Pop Goes the Weasel." When the clown emerges, the user's heart will stop out of fear for half a second. However, after use, the user, if they ever experienced coulrophobia, will be cured. No other effects, other than those potentially caused by the heart's stop, have been recorded.