On the artist request, this is the oldest full size post of this image I could find (with minor differences). A reply credits this archived /co/ thread wherein the image now reads "The requested URL was not found on this server." for me. User in thread doesn't explicitly claim to've made the image and is anonymous regardless.
User in thread doesn't explicitly claim to've made the image and is anonymous regardless.
Switching the archive from Fireden to Desuarchive enabled me to use the 'View Same' image option. While that thread is the earliest result, the second-earliest result of someone asking the same question of source has another anon responding that another anon had confirmed they had drawn it. So, unless provided with evidence that this isn't the case/evidence of what that anon's handle could be, we can probably apply the usual artist tag for this.