瓦沙克（英语：Vassago），是所罗门七十二柱魔神中排第3位的魔神。瓦沙克在恶魔的世界传闻是一位强大的王子，称号“予言贵公子”，统帅第26个军团。据说通晓过去现在未来之事，会被寻求智能之人所召唤，能够发现被隐藏或丢失的事物。拥有一个良善的本质，是恶魔中少数的性格温和者，通常会以披着长袍的贤者姿态出现。

有人将他的外表描述得和阿加雷斯（Agares，所罗门七十二柱魔神中的第2柱）一样，所以经常把两者视为同一位魔神。也有另一种说法说他的脸如同一个倒三角形的头盖骨，延伸到下颚的两眼看不见任何物体，但是却能透过异次元而看见过去未来。他也是知识探求者们常会召唤的恶魔之一。

Vassago (also Vasago, Usagoo) is the third Goetic demon described in the Lesser Key of Solomon (including Thomas Rudd's variant) as a prince "of a good nature" (despite being a demon) and of the "same nature as Agares". He rules twenty-six legions of spirits, and is summoned to tell magicians of past and future events, and locate lost objects. He is one of the few spirits found in the Lesser Key of Solomon but not in Johann Weyer's Pseudomonarchia Daemonum. Vassago is mentioned in the Book of the Office of Spirits as Usagoo, appearing as an angel, "just and true in all his doings," with the powers of inciting the love of women and revealing hidden treasures, in addition to ruling twenty spirits. Sloane MS 3824 mentions Vassago in invocations to summon spirits that guard treasure, and in the "Experiment of Vassago" and the "Experiment of Agares," both intended to capture the named spirits in crystals. According to Rudd, Vassago is opposed by the Shemhamphorasch angel Sitael.