Berith

Historical Note: The name Berith (Berich) is probably derived from 'Baal-Berith' in Judges 8:33.

Goetia - S. L. MacGregor Mathers (1904)

The Twenty-eighth Spirit in Order, as Solomon bound them, is named Berith. He is a Mighty, Great, and Terrible Duke. He hath two other Names given unto him by men of later times, viz.: BEALE, or BEAL, and BOFRY or BOLFRY. He appeareth in the Form of a Soldier with Red Clothing, riding upon a Red Horse, and having a Crown of Gold upon his head. He giveth true answers, Past, Present, and to Come. Thou must make use of a Ring in calling him forth, as is before spoken of regarding Beleth.17 He can turn all metals into Gold. He can give Dignities, and can confirm them unto Man. He speaketh with a, very clear and subtle Voice. He governeth 26 Legions of Spirits. His Seal is this, etc.

Pseudomonarchia daemonum - Johann Wier (1583)

Berith is a great and a terrible duke, and hath three names. Of some he is called Beall; of the Jewes Berithi; of Nigromancers Bolfry: he commeth foorth as a red souldier, with red clothing, and upon a horsse of that colour, and a crowne on his head. He answereth trulie of things present, past, and to come. He is compelled at a certeine houre, through divine vertue, by a ring of art magicke. He is also a lier, he turneth all mettals into gold, he adorneth a man with dignities, and confirmeth them, he speaketh with a cleare and a subtill voice, and six and twentie legions are under him.

Dictionnaire Infernal - Collin de Plancy (1863) 

Berith is a great duke of hell governing 26 legions. He is called Beal, Berith by the Jews, and Bolfri by necromancers. He is also worshipped by the Sichemites, and possibly the same as Beroth of Sanchoniaton, whom some believe to be Pallas or Diana. He appears as a soldier dressed in red, riding a red horse and wears a crown on his head. One must have a magic ring to control him. He knows of past/present/future events, gives dignities, aids in singing ability, and is often known as the demon of the alchemists for his avidity to change metals into gold.

According to the author of Solide tresor du Petit Albert, Berith is no more than a goblin or elf.

"I found myself, he said, in a house where a familiar spirit had manifested for six years taking car eof winding the clock and currying the horses. I was curious one morning to examine these proceedings: my astonishment was great to see a curry-comb running over the hindquarters of a horse which appeared to be done by no visible hand. The groom told me that to attract the familiar to his service, he had taken a small black chicken, which he had bled at a great crossroad; that with its blood he had written on a scrap of paper: 'Berith will come to my aid for twenty years, and I will recompense him;' next having buried the chicken a foot deep in the earth, that same day the familiar had taken care of the clock and some horses, and that from time to time game the groom things which were worth something…"

Others believe him to be a mandrake or a sylph.