Fossa

The Fossa looks like a cat with a long, slender body and a long tail. It has flexible ankle joints and retractable claws for climbing quickly on trees. It lives in the Madagascar rainforests; its main diet is rodents, birds, and reptiles. After the rainforests turn into grasslands, the Fossa will have to adapt. It will have a shorter tail and longer legs; they will also shrink in size. They will have shorter tails because there won't be many trees to climb, so there would be no use for a tail, it would just slow them down. They would have longer legs to catch their prey and shrink to take up less space, energy, and food. In addition, they will match the color of the grass they live in and be able to live without eating and drinking for two weeks. Their ears will also grow for better hearing.