Jo and Mo Redd-Zoff are two brothers who are professional World-Champion Sleep-Talkers from the book Dr. Seuss's Sleep Book.
Instead of lying in bed sleeping they are sitting up in bed sleep-talking to each other. To them sleep-talking seems to be a wonderful sport and they have done it for 55 years all night every night. Their conversations happen to be about laws, gauze. paws, flaws and have even talked quite a lot about old jolly Santa Claus.
The long tailed creature in the book at the beginning tells the viewers that they should take up a sport like that cause its a fine workout for the Jaws.