Madame Cee is a tinkerer extraordinaire. From the workshops on her island, Madame Cee can create any sort of robot her mind can conceive. Mostly, this means pigs; she's obsessed with robot pigs.
Madame Cee is an imposing figure with very pale, almost grey skin, mesmerising eyes that flash like pearls, and a dress that shimmers like molten lead. Her striking appearance can overwhelm an unprepared individual, who will find himself following her unquestioningly. Once aware of the effect, a disciplined mind can override it.
For all their mechanical sophistication, Madame Cee's creations are ultimately automatons, lacking any mind of their own. Megatron found it necessary to rewire them with sophisticated computer brains programmed to obey him.
Seeking out Madame Cee for her expertise in robotics (as well as the high quality metallic ore on Carob Island), Megatron forced her to build replicas of various Autobots, which he refitted to commit acts of destruction. Madame Cee had a considerable dislike for Megatron, but once he moved out of her fortress, setting up shop to the west, she was content to fabricate the parts he wanted in exchange for Decepticon diggers mining the ore she needed... as long as she didn't have to deal with the Decepticons directly.
When the Autobots came to Carob Island seeking to clear Sideswipe of crimes committed by his clone, Madame Cee captured Hound and Bumblebee, intending to rebuild them into more pig robots. She led Prowl, Ratchet, Brawn, and Windcharger to her fortress, where Prowl discovered her role in building robot duplicates. Fending off an attack by Ravage, Prowl forced her to reactivate Hound and Bumblebee, and give them directions to Megatron's base.