The Jetsons are a family of people from the future that starred in the show of the same name. They have made many cameos in Drawn Together.
In Hot Tub, a flying aircraft similar to the ones they use in the show was seen flying overhead.
In Foxxy vs. the Board of Education, Elroy was one of the children being kidnapped by Hans the six armed child molester.
In A Tale of Two Cows, the Drawn Together gang went to the Skypad apartment in search of Live Action Cow, where they found that all of the Jetsons have been killed by her. Rosie was also seen holding the dead body of Elroy and crying.
In Toot Goes Bollywood, although none of them actually appeared, Foxxy Love addressed Scooby Doo as Astro.