This deal from Wowcher
From £29 for a deep-filled spring unicorn mattress in small single, single or small double sizes from Desire Beds!
Girl’s mattress: Get an adorable dual-sided mattress – made with breathable, hypoallergenic and anti-dust mite fabric. Unicorn design: Your little one will fall in love with the whimsical design – featuring unicorns and stars! Comfortable: Deep-filled with seven generous layers of luxurious and comfortable padding. Spring mattress: With a European engineered traditional 13.5 gauge open coil spring unit. Support: Gives a great level of support – perfect to give any growing child a peaceful night’s sleep. Sizes: Get a Small Single, Single or Small Double mattress – perfect for a children’s bedroom.