A small ice and snow-covered moon orbiting a vast gas giant is home to the Decepticon penal colony called Styx. Of all such installations it is the harshest and most brutal. Prisoners sent to Styx have a short life-expectancy and may be better off for that. The penal colony is said to be impregnable.
Gutcruncher is stationed there.
IDW comic continuity
Hot Rod impregnates the impregnable prison (get your mind out of the gutter) with a virus that lets him sneak in and free his former comrade, Dealer.
Although Dealer seemed appreciative, he failed to give Hot Rod a "Domo arigato".