Astaroth

Goetia - S. L. MacGregor Mathers (1904) 

The Twenty-ninth Spirit is Astaroth. He is a Mighty, Strong Duke, and appeareth in the Form of an hurtful Angel riding on an Infernal Beast like a Dragon, and carrying in his right hand a Viper. Thou must in no wise let him approach too near unto thee, lest he do thee damage by his Noisome Breath. Wherefore the Magician must hold the Magical Ring near his face, and that will defend him. He giveth true answers of things Past, Present, and to Come, and can discover all Secrets. He will declare wittingly how the Spirits fell, if desired, and the reason of his own fall. He can make men wonderfully knowing in all Liberal Sciences. He ruleth 40 Legions of Spirits. His Seal is this, which wear thou as a Lamen before thee, or else he will not appear nor yet obey thee, etc.

Sacred Magic of Abra-Melin the Mage - SL MacGregor Mathers (1898) 

Astarot: From Hebrew, OShThRVTh, = flocks, crowds or assemblies. Usually written “Ashtaroth”. Also a name of the Goddess Astarte; Esther is derived from the same root.

Pseudomonarchia daemonum - Johann Wier (1583) 

Astaroth is a great and a strong duke, comming foorth in the shape of a fowle angell, sitting upon an infernall dragon, and carrieng on his right hand a viper: he answereth trulie to matters present, past, and to come, and also of all secrets. He talketh willinglie of the creator of spirits, and of their fall, and how they sinned and fell: he saith he fell not of his owne accord. He maketh a man woonderfull learned in the liberall sciences, he ruleth fourtie legions. Let everie exorcist take heed, that he admit him not too neere him, bicause of his stinking breath. And therefore let the conjuror hold neere to his face a magicall ring, and that shall defend him.

Dictionnaire Infernal - Collin de Plancy (1863) 

Astaroth appears as an ugly angel riding a dragon and holding a viper in his left hand. It is thought that this powerful grand-duke presides over 40 legions, and possibly over the East and is treasurer of hell. The Sidonians and Phlistines worshipped him in the past. Wierus mentions that he knows of past and future events, secret things, liberal arts, and the story of creation and the fall of the angels. He also believes he received an unjust punishment. Some magicians say he procures the goodwill of great lords and can be summoned on Wednesday. He is said to emit a powerful fetid odor, and to endure that, the magician should hold a silver magical ring that prevents odors under his nose.

Astaroth is cited as one of the seven princes of hell who visited Faust, appearing as a serpent with a colored tail, two small feet, a chestnut neck, and spines similar to a hedgehog that can grow up to a finger's length. As his feminine counterpart, Astarte, he is portrayed with a heifer's head.