Jack Hanna is a famous wildlife expert, and a longtime friend of David Letterman. He appears on Letterman's show several times a year, always bringing a random exotic animal along with him. Tonight on the 'Late Show' (weeknights, 11:35PM ET on CBS), Jack arrives with a one-year-old cheetah, and plops the enormous creature right on top of Dave's desk.

Jack also brings along a type of animal that cheetahs are "deadly afraid of," but you might have a hard time guessing what that animal is. Cheetahs can reach speeds in excess of 70 miles per hour; they kill their pray by snapping their throats. The big cats are fairly deadly. So what would scare a cheetah? A lion? A crocodile? A blue whale?

(S05E17) As I got into this episode, two things occurred to me. First, since next week is the season finale, when did they decide to cut this season to 18 episodes? More importantly for our purposes here though, this episode felt very familiar. It took a minute, but when Lois and Mayor West got to the debate, I remembered what it was. The main story was very similar to the season two episode, "Running Mates."