The Goetia reports of the demon Andras: "He is a Great Marquis, appearing in the Form of an Angel with a Head like a Black Night Raven, riding upon a strong Black Wolf, and having a Sharp and Bright Sword flourished aloft in his hand. His Office is to sow Discords. If the Exorcist have not a care, he will slay both him and his fellows. He governeth 30 Legions of Spirits."
Some explanation may be useful in clarifying this description. By a night raven, an owl is intended. Black wolves were once fairly common in Europe. Both wolf and owl were considered to be animals of evil.
The magician performing the evocation is called the "exorcist" in the English translation of the Goetia preserved in manuscript in the British Library (Sloane ms. 2731). We would not apply the term exorcist to the magician today since the magician is calling the spirit forth to visible appearance, rather than driving it away. However, the term exorcist was once used more generally to describe someone who commanded spirits. Magicians traditionally had at least one assistant, usually more than one, to help them in their rituals. They stood inside a magic circle for protection -- if the evoked demon could tempt or deceive the magician or his assistants to step out from the circle, the demon could then injure the careless human beings.