Roti was a protein-rich grain native to the planet Serat. It was the staple of the Seratian diet. As the Seratian population expanded, it displaced other native animal life, notably the forest tymp. Over the decades and centuries, a new sub-species evolved, known as the urban tymp. Unlike wild forest tymps, urban tymps were able to digest roti and scavenged farms and urban areas. In response, the Seratians began guarding roti in durasteel silos.