On August 13th, 2019, Adult Swim, a Warner Bros.-owned channel announced that they had picked up Loonatics Unleashed for 30 new half-hour episodes that will begin airing on November 13th, 2019. The returning crew will be larger than the original crew.
It was announced that the original voice actors Schlatter, DiCicco, Marsden, Paulsen, Richardson, and Milo would return as well, but during production of the episodes, it was announced that a casting notice was posted to replace the entire cast when Warner Bros. Animation would not meet their salary demands. The situation was later resolved, and the entire original voice-cast returned for the new episodes.
Near the end of a message from Rob Paulsen sent to members of the "Save the Voices of the Loonatics" group on Facebook, Paulsen announced that the original cast would be returning for the new episodes.
The cast from the first 2 seasons reprise their roles.
Animation for this season is done overseas at Hanho Heung-Up Co., Ltd. in South Korea and Mook Animation in Japan.
Due to the critical acclaim of this season, two more seasons were greenlit.
- This season has been shown to be much more successful than the ones that preceded it, as it received positive reviews.