Worldcleaver Scornforge
(unless I decide to change the name)
This mothership is similar to the Star Forge from SW:KotOR in being able to create an unlimited supply of battleships, but it also works as a superweapon that can pierce naughty planets with its claws and devour their cores with its core. Its size is about equal to that of a sun from which it can also draw power. The more planets fight back, the more energy it receives to power the construction.