Sit . Unfold . Sleep Hippo is a comfy futon chair that can easily be converted into a mattress. By releasing the back of the chair and lifting up the arms, Hippo lays out flat, becoming a thick, rich mattress that’s perfect for guests and sleep-overs. Design by Anders Backe, Anne-Sofie Voss, Ida Sofie Lange, Lars Wigh and Troels Rask Pedersen for Karup Design. Note that all of our futon products are handmade, so you might notice small differences in size and weight.