Furniture designer Seungji Mun created his amusing Cat Tunnel Sofa to "share feelings with a cat." Mun is based in Korea, where an estimated 10 million people are pet owners; for scale, the entire population of Seoul is 10.4 million.
Space is tight in Korea, particularly in Seoul, and purchasing cat-specific furniture like you'd see in an American pet shop isn't a viable option for most families. Mun hopes his design will kill two birds (like your cat wishes he could) with one stone.
Mun, if you're reading this, advice from New York City: I often see discarded furniture lying curbside, and Manhattan's Crosby Street in particular, near Core77's offices, seems to be a dumping ground for unwanted sofas. They're often in mostly excellent shape, but I'd say at least 75% of them bear clear signs of why they were thrown away—cat-shredded sides. Incorporate some claw-friendly materials for the vertical surfaces and I think you've got a winner.