I don't know much, but I can tell you a brief about early Krokotopia,
For thousands of years, Krokotopia was once land to the Mander Race. Until one day, a land risen upon the Manders. The land contain Kroks, tired and hungry from their trek. They began to capture the hospitality of the Manders. They unleashed cruelty onto the Manders, and from there the Mander Race lived under the ruling of the Kroks.