There is an independent image for this degree from 1898, decades before the Sabian set existed. Charubel's book puts it this way: a human skull. Counting from Scorpio's start, this is the second degree, placing it in the sign's first decan. Its decan is ruled by Mars, Scorpio's own planet, reinforcing rather than complicating the sign's usual character. The term ruler here is also Mars, so the finer division agrees with the decan rather than adding a separate voice.
The degree symbols themselves date to 1925, when Marc Edmund Jones and the clairvoyant Elsie Wheeler sat in Balboa Park, San Diego, and drew all 360 blank cards in random sequence so that no degree's image could be planned in advance. Jones published his findings in 1953, yet the reading in general circulation since is Dane Rudhyar's 1973 restatement, not Jones's own words, and Rudhyar's text is still in copyright and is not quoted on this page.
As the middle water sign, Scorpio does not merely feel; it investigates, and it does not let go easily. What a degree reading offers here is orientation rather than forecast, a way of naming exactly where in Scorpio's cycle a person or moment sits. Element and quality carry through every degree of Scorpio: it is a fixed water sign, and this degree inherits that basic temperament even as the decan and term add their own note.