This house is where Cosmo grew up, raised by his mother, Mama Cosma, and father, Papa Cosma. After Cosmo accidentally turned his father into a fly, and later ran away to marry Wanda, Mama Cosma was left alone. She created two robots, Star and Twinkle, in attempt to tempt Cosmo back into her home.
Mama Cosma's House first appeared in "Apartnership!". After a brief spat with his wife, Cosmo ran away back to his mother's home in Fairy World. Wanda and Timmy Turner followed him here and tried to convince him to return to them, but Mama Cosma only made the situation worse.