the first three months, more than 300,000 units were sold across the country. Because of market and media saturation of this toy, any such ball, regardless of origin, is now generally known in the US by that name. The earliest Hoppity Hops were made of rubber (usually red or blue) with a round ring handle on top and an automotive tire valve for inflation. In the 1970s, Sun introduced various character versions of the Hoppity Hop, such as the Hoppity Horse or Disney's Mickey Mouse and Donald Duck (with hard plastic versions of the character's head attached to the ball). The Hoppity Hop sold steadily for decades, but by the 1990s, sales began to slip due to increased competition from foreign hoppers. According to advertising materials, the Hoppity Hop's original targets were both adults and children. Since the balls only inflated to around , however, it is doubtful that any but the shortest adults could have gotten much use out of one. The European "Hop!" balls appeared in the beginning of the 1990s and are still available. Made by Italy's Ledragomma/Ledraplastic, these are essentially an exercise ball with a handle attached. The sizes of these balls range from the "Hop! 45" to the "Hop! 66" (66 cm, about 26 in). The Hop! 66 is still primarily child-sized. Demand for truly adult-proportioned hopping balls was met with two notable items: The first was Kitt 2000 Velp, of the Netherlands Mega Skippyballs, a large hopping ball that, by virtue of its size, was intended only for adult use. It came in three sizes: , , and . The Mega Skippyballs are made of extra-strong vinyl, and in the Netherlands, there are various Skippyball races and championships. Popular culture Terry Cooper's humorous science fiction trilogy Kangazang features space hoppers (referred to as "Hoppas"), who are depicted as an alien race living on the planet Profania Alpha. Space hoppers appear in the background of one scene in Episode 59 of Star Trek: The Original Series, "And the Children Shall Lead". Episode 12, season 2 of the 1970s British comedy The Goodies was mostly related to space hoppers. In a season-7 episode of Friends, "The One Where They All Turn Thirty", Phoebe bounced for a mile on a Hippity Hop. In Doctor Who, series 3, episode 11, "Utopia", the Tenth Doctor refers to Captain Jack's Vortex Manipulator as a space hopper in contrast to his