Mewhu is an extraterrestrial humanoid whose spaceship crashed on New Jersey, Earth, in a seaside cottage where a Human family was vacationing, in the mid-20th century. The family consists of Jack Garry, his wife Iris, and young daughter Molly, who befriended the alien and with whom he established a telepathic link to communicate.
Physically, Mewhu is a man-sized humanoid, estimated to weight over 77 kg. He has silver-colored skin and a grey mustache. His eyes are also silver and have a transparent nictitating membrane. His pupils contract in the presence of light, much like a cat's. His skeletal structure is noticeably different from Humans, as he has only one bone in his forearm, and therefore a ball-and-socket-like joint in his wrist. His hands have six fingers.
His teeth are widely-spaced and pointed, and he appears to smile to express positive emotions in a way similar to Humans. His tongue is pointed in shape, light-orange in color, and described as "four inches longer than it had any right to be".
Mewhu produces cat-like noises, as well as other types of vocalizations which constitute his own language, although he cannot pronounce the "ah" vowel and therefore replaces it with others (e.g. pronouncing Jack's name as "Jeek"). However, his principal means of communication is telepathy, which he can establish with a few select individuals, such as Molly Garry.
In terms of internal anatomy, it's known that he has two hearts and two closed circulatory systems, and that his arterial blood is purple. Like Humans, he seems to require sleep. He can consume food such as eggs, toast and bacon with no problems, but consuming aspirin makes him agitated and has an inebriating effect similar to that of alcohol.
According to a hospital doctor who treated Mewhu after an accident, his biological healing reactions are akin to those of a child, allowing him to recover from injuries better than an adult individual could. This evidence, coupled with Mewhu's very childlike behavior and his peer-like bond with Molly, has led Jack to conclude that Mewhu is indeed a child of his species, and thus can't be expected to know how to operate the technology that brought him to Earth (most likely by accident) in the first place.
- "Mewhu's Jet", by Theodore Sturgeon (1946)