UK-based Funky Little Darlings are like Wall Murals Gone Wild (lifts up shirt)!! Big, bold, comic book/manga-esque, the rooms above are real kids rooms that they've created full-scale murals for and, in some cases, did interior design.
In their custom work they incorporate the child's interests and hobbies like skateboading and Italian race cars or a modern spin on fairies for the playroom of three sisters. When founders Many Colliss and David Quinton started out they hand-painted their murals, but after "[seeing] the look on peoples faces when we turned up for the eleventh consecutive day" they found a company to produce wallpaper murals that could be hung like traditional wallpaper.
Funky Little Darlings also sells wallpaper murals as a way for customers to achieve the look of their custom work for less. Though we're pretty sure we couldn't commit to something as large and loud as these, we bet kids like them and their site is fun for inspiration.