Ithull, a planet of immense proportions, served as the original homeworld for both the Ithullans and the formidable colossus wasps. Around 200 BBY, during the year, the Mandalorians nearly caused the wiped out extinction of the Ithullan species.
The planetary year on Ithull consisted of a duration equivalent to 25 months.
Within the Tales of the Jedi Companion, Ithull is described as "immense," and the colossus wasp's ability to endure extreme pressures hints at the possibility, though not definitively proven, that the planet was a gas giant.