It may be possible that this goat figure, Leonard, is related to the ritual described in Leviticus 16:8 concerning Azazel, or to the alleged deity of the Templars, the Baphomet/Goat of Mendes.
There is mention of a “Master Leonard” in the Dictionary of Phrase and Fable (1898)
Grand-master of the nocturnal orgies of the demons. He is represented as a three-horned goat, with black human face. He marked his novitiates with one of his horns.- Dictionary of Phrase and Fable
He is also mentioned in Eliphas Levi’s (1810-1875) Ritual of Transcendental Magic (published 1896), Chapter XV, “The Sabbath of the Sorcerers:”
To Sabbaths dreamed in this manner we must refer the accounts of a goat issuing from pitchers and going back into them after the ceremony; infernal powders obtained from the ordure of this goat, who is called Master Leonard; banquets where abortions are eaten without salt and boiled with serpents and toads; dances, in which monstrous animals or men and women with impossible shapes take part; unbridled debauches where incubi project cold sperm. Nightmare alone could produce or explain such scenes. – Ritual of Transcendental Magic, xv. 312
Dictionnaire Infernal – Collin de Plancy (1863) (paraphrased)
Often called “le Grand Negre” (The Black Man), Leonard is demon of the first order, grand master of the sabbaths, chief of the subaltern demons, and inspector general of sorcery, black magic and witchcraft. From the waist up, Leonard has a goat’s body with 3 horns on his head, a goat’s beard, hair-like bristles, 2 ears like foxes, and inflamed eyes. He also has a face on his butt, which witches kiss while holding a green candle to adore him. Leonard can take the form of a bloodhound, a beef, a black bird, or a tree trunk with a gloomy face. When he attends the sabbath, he has the feet of a goose, although experts claim that he has no feet when in tree trunk form. Leonard’s attitude is reserved and melancholic, but when he appears at witch and devil assemblies, he is commanding and uses situations to his advantage.