Hugh Rankin and "The Silver Key"

Though the covers of Weird Tales are usually more well remembered by history (for obvious reasons), it should be remembered that most of the stories published within the Unique Magazine had at least one accompanying illustration. So it is with H.P. Lovecraft's "The Silver Key," which featured this piece of artwork by Hugh Rankin.

Rankin provided illustrations for dozens of stories during the 1920s and '30s, including many by Lovecraft and Robert E. Howard. Perhaps his most significant one may be one from "Pickman's Model," depicting a ghoul.
I can't say with absolute certainty that this is the first ever depiction of one of Lovecraft's ghouls in a publication, but I suspect that it is. That alone makes Rankin worthy of remembrance. 
(I feel compelled to add Lovecraft's own drawing of a ghoul, which he drew in 1934, years after the publication of "Pickman's Model." I find it strangely charming.)