This is a project I offer my students after we've done a lot of life science. Be sure they have experience with adaptation, as well as delving into different types of habitats.
I make cards with an animal and a habitat (both of which I have resource books for the students to use). Be sure that the habitat and the animal do NOT match. Examples: Polar Bear/Desert, Sea Otter/ Savanna, Gorilla/Tundra.
Students will research their animals and that animal's actual habitat, focusing on how it has adapted for survival. Then, they will research the new habitat on their card and imagine how their animal would have to adapt to survive the new habitat.
Finally, they will create their new animal on paper, on computer or as a 3D model.
With all of this, they will present their findings and creations to the class.