First of all: I am not a lawyer, so I base my answer on what I understand of US copyright law, and I might be wrong in details.
generally speaking YES
No licensing can forbid you from making your own art, but Trademark and Licensing Agreement may restrict you from naming it (in public) after the Product Identity or prohibit publishing.
Like... I could draw a picture of a person in brown robes, wielding a blade that emits green light. But I would neither be allowed to call the figure on the picture Luke Skywalker with his lightsaber, as both the name of the weapon and the characters are PI and Trademarks of LucasArts, nor am I allowed to publish it if it is clear enough that it is this IP/TM. That stuff is mostly covered over at the other question linked in this question.
There is also the other shoe we have to look at: you could violate copyright if you make something substantially similar or copy the other picture and then publish it in any waysome exceptions. What is substantially similarity? And what publishing?
Well, substantial similarity is the standard for "is this a copy or not". There is a rather good wiki entry on it, and there is an even better explanation from lawyers, but it boils down to a test: "Does this look like the other? Does it copy the style? Does it tell the same story?" or, to quote the lawyers, this test's
goal is to determine whether an ordinary observer, "unless he set out to detect the disparities [between the works], would be disposed to overlook them, and regard their aesthetic appeal as the same." See Peter Pan Fabrics, Inc. v. Martin Weiner Corp., 274 F.2d 487, 489 (2d Cir. 1960).
But substantial similarity can not cross a media gap as far as I know, and especially not between text and visual, for a picture conveys its message so differently than text. But careful: a movie is a "motion picture" and thus a still picture of a still is not crossing the gap. A digital picture is just like a real one.... But let's take an example. This description would fit several hundred or thousand pictures, both photos and drawn:
He is of a little below average hight and slender, his blond hair hangs shaggy in front of his blue eyes. His chin has a grove and when he smiles, which he seldomly does, there are dimples on his cheeks.
Even I could draw several pictures that all match this description, and none would be substantially similar to the other for using different styles or by putting them in different context. And yes, this text could also be used to describe that very Luke Skywalker I had used up there as an indicator that there are PI/TM to look out for.
If you base your pictures on the textual descripion, I know of nothing making the resulting picture a copyright violation. If you re-paint the original illustration though and publish it, you violate licensing and copyright.
Let me quote the wiki:
Publishing is the dissemination of literature, music, or information—the activity of making information available to the general public.
Key point is general public. It doesn't matter if it is comercial or not, it matters, that it is available for the general public. Which means pretty much: "Can I go to a public place and access the work, either by looking at it or acquiring a copy?" The Internet is such a public place. Your hobby cellar is most certainly not, as it is not open to the general public.