Claude Coats was a man of unknown species, who is presumably now a ghost.
Claude Coats is one of the "great ghost writers" whose books are kept in the Haunted Mansion's Library. He wrote a two-volume masterwork entitled The Art of Deception. It is unclear if he was, in life, the same Mr Coats whom the Ghost Host once spoke of as one of the two architects who originally built the Mansion, but it is very likely that he is also the author of Primates of the Caribbean, a book available in the Skipper Canteen.
Behind the scenes
Claude Coats's name, an allusion to the real-life Imagineer Claude Coats (who contributed greatly to the Mansion’s creation), appears on the spines of the two volumes of The Art of Deception as seen in the Walt Disney World ride The Haunted Mansion, which opened in 1971. Another book by "Coats" was added to a different attraction in 2015: the Jungle Navigation Co. Ltd. Skipper Canteen, a themed restaurant part of the Society of Explorers and Adventurers megatheme.