The first season was actually completed in 1983, but was not publicly shown until two years later.
The TV movie "Thundercats Ho! The Movie (1987)" was planned as a big-screen movie for theaters. However when films like "Transformers the Movie" and "My Little Pony the Movie" had bombed, they got cold feet and released it as a TV movie. It later got split up into five parts. The dvd release on the season sets is the cut-up five-part version. It has never been released uncut on dvd.
At the end of each episode Lion-O, Cheetara, Panthro and some of the other good guys in the series, give the younger viewers tips and advice about life.
The setting of many of the installments of "ThunderCats" was described as "THIRD Earth." The present day was referred to as "FIRST Earth."