The demon Onoskelis appears in the grimoire Testament of Solomon
From Testament of Solomon, Joseph H. Peterson edition:
And when she was come, I said to her: "Tell me who art thou?" But she said to me: "I am called Onoskelis, a spirit wrought ...shabtai, lurking upon the earth. There is a golden cave where I lie. But I have a place that ever shifts. At one time I strangle men with a noose; at another, I creep up from the nature to the arms. But my most frequent dwelling-places are the precipices, caves, ravines. Oftentimes, however, do I consort with men in the semblance of a woman, and above all with those of a dark skin. For they share my star with me; since they it is who privily or openly worship my star, without knowing that they harm themselves, and but whet my appetite for further mischief. For they wish to provide money by means of memory, but I supply a little to those who worship me fairly."
And I Solomon questioned her about her birth, and she replied: "I was born of a voice untimely, the so-called echo of a man's ordure dropped in a wood."
And I said to her: "Under what star dost thou pass?" And she answered me: "Under the star of the full moon, for the reason that the moon travels over most things." Then I said to her: "And what angel is it that frustrates thee?" And she said to me: "He that in thee is reigning." And I thought that she mocked me, and bade a soldier strike her. But she cried aloud, and said: "I am subjected to thee, O king, by the wisdom of God given to thee, and by the angel Joel."