A 20-year-old known as Nano thinks she is a cat trapped in a human's body.
She believes she has cat-like characteristics, like sharpened hearing and night vision.
Below she spoke to a Norwegian TV outlet and described her everyday life:
She points out that it's obvious she's a cat when she purrs and meows. Nano says she first realized she was a cat when she was 16 years old and doctors told her they found a "genetic defect" in her DNA.