Goetia – S. L. MacGregor Mathers (1904) (quoted)

Orobas’ Goetic seal

 
The Fifty-fifth Spirit is Orobas. He is a great and Mighty Prince, appearing at first like a Horse; but after the command of the Exorcist he putteth on the Image of a Man. His Office is to discover all things Past, Present, and to Come; also to give Dignities, and Prelacies, and the Favour of Friends and of Foes. He giveth True Answers of Divinity, and of the Creation of the World. He is very faithful unto the Exorcist, and will not suffer him to be tempted of any Spirit. He governeth 20 Legions of Spirits. His Seal is this, etc.
Pseudomonarchia daemonum – Johann Wier (1583) (quoted) 
Orobas is a great prince, he commeth foorth like a horsse, but when he putteth on him a mans idol, he talketh of divine vertue, he giveth true answers of things present, past, and to come, and of the divinitie, and of the creation, he deceiveth none, nor suffereth anie to be tempted, he giveth dignities and prelacies, and the favour of freends and foes, and hath rule over twentie legions.
Orobas – Dictionnaire Infernal

Dictionnaire Infernal – Collin de Plancy (1863) (paraphrased) 
High prince of hell, Orobos commands 20 legions. He appears in the form of a beautiful horse or as a man, who speaks of the divine essence. He knows of the past/present/future, can discover falsehoods, grants favors and help, and can reconcile enemies.