The Spirit of the Forest by =Tiretin on deviantART
Katie King was the name given by Spiritualists in the 1870s to what they believed to be a materialized spirit. The question of whether the spirit was real or a fraud was a notable public controversy of the mid-1870s.
The spirit was said to have appeared first in 1871 in séances conducted by Florence Cook in London, and later in 1874-1875 in New York in séances held by the mediums Jennie Holmes and her husband Nelson Holmes.
Katie King was believed by Spiritualists to be the daughter of John King, a spirit control of the 1850s through the 1870s that appeared in many séances involving materialized spirits. A spirit control is a powerful and communicative spirit that organizes the appearance of other spirits at a séance. John King claimed to be the spirit of Henry Morgan, the buccaneer (Doyle 1926: volume 1, 241, 277).