Fool your friends

Have you heard of puzzle jugs? They were essentially joke shop fare, regardless of whether there were actual joke shops back then. The most popular tended to be something like a dribble glass. The unwary toper would lift them to take a drink, and then find himself drenched.  But there were other variations. According to Kovel's American Antiques (2004 edition):

One jug, the simplest of puzzles, had a frog on the bottom. When the unwary tippler drank his grog, the frog appeared―a startling, lifelike visitor. Many hard drinkers must have had a real fright from this jug.

The urge to prank goes back far, further than this entry might indicate. It's a healthy instinct, in the right context. One hopes that the wags have not been forever stilled.