This was a secret association that was imported into Germany, which celebrated the Gnostic sabbath. It replaced the Kabbalistic “goat” with the Hermetic “dog” as the object of worship. (see Hermes Trismegistus) The candidate for the order was brought into the circle of adepts with eyes bandaged in the midst of a great uproar, and after saluting the idol was initiated. The sign of recognition was a grimace. The Mopses recruited only among Catholics, and for the oath of reception they substituted a solemn engagement of honor to reveal no secrets of the order, a customary practice of the Sabbath orders of medieval sorcerers. A.G.H.
Source: 81, 279.