"Retro" is the fiftieth episode of Lilo & Stitch: The Series. It aired on May 20, 2005.
Nani's middle school friends, Ellen and Lona, return to Kauai for a visit and, thinking that Nani is vice president of the business she works for (which is clearly not true), invite her and her ʻohana on a yacht cruise. Meanwhile, Stitch encounters an experiment that reverts individuals to a primitive state. Lilo, Jumba, Pleakley, Ellen and Lona are transformed into cave people, which causes trouble on the yacht.
- Moral: Be yourself.
- Music from The Land Before Time sequels can be heard several times during this episode.
- Nani's junior high friends, Ellen and Lona, are revealed to live in New York and Los Angeles respectively.
- Technically speaking, Nani didn't lie about being rich, though Ellen and Lona jumped to false conclusions before Nani could explain.
- The saber-toothed squirrel is a reference to Scrat, a character from the Ice Age movies.
- This is the only episode where Nani is at fault, as opposed to Lilo and/or Stitch.
- The wildlife preserve is a parody of the one from the 1993 sci-fi film, Jurassic Park.
- At the end of this episode, Lilo even mentions that the wildlife park reminds her of a movie she once saw, which is referenced by a living T-Rex that Retro reincarnated by unknown means, a nod to said film.
- The T-Rex was possibly reincarnated from a chicken or some other species of bird, since birds are said to have descended from dinosaurs.
- Gantu, Reuben and Hämsterviel do not appear in this episode.
- In "Woops", Retro erroneously appeared with Gantu's other captive experiments, but he was captured by Lilo and Stitch.