Q: What is the smartest animal?
A: A snake, because no one can pull its leg!

Explanation: There are a lot of smart animals!  (My cat was not one of them, but I loved him anyway.) Snakes are not generally included in lists of the smartest animals.  In this joke, though, they are the smartest.

To pull someone’s leg is an idiom that means to fool a person, usually in a fun or harmless way (in Spanish: tomar el pelo a alguien).  If someone told you she just got tickets to go to the space station, you might say, “Stop pulling my leg; you did not.” Of course a snake would never say that because snakes do not have legs.

This joke is funny because it plays with two meanings of pulling one’s leg: the literal meaning of actually tugging on someone’s leg and the idiom meaning to fool someone.  Maybe someday with genetic engineering you will be able to pull a snake’s leg… nah, I’m just pulling your leg. That’ll never happen.

Here is a smarter than average snake: