Who the hell is Fritzen Ravenswood, and why did this writer produce only two Zebra paperbacks? I don't think anyone knows. First, "Fritzen Ravenswood" is, obviously, a pen name* (update: actually, it's not; see comments below), but what a pen name (why, it's more impressive than Garth Marenghi). At least, I think it's a pen name; don't you? I suppose it's entirely possible the author's parents foresaw their child's future as a pulp horror author, and wanted to provide the kid with an appropriately morbid moniker. The titles of the only two works attributed to Ravenswood, The Spawning and The Witching, both published in 1981, feature the gerund form that was inescapable in cheap horror novels post The Shining.
The Other - bathed in blood with the tagline They were the children of her demon lover. Coool. For The Witching, there are exquisitely detailed hands bound together... Obviously these two novels were published before Zebra's famously ridiculous skeletons began cavorting about the covers in all manner of scenarios. Like this one:
Although I don't think the skeleton here is cavorting as much as he is frozen in utter embarrassment...
The Invisible Man (2017)
35 minutes ago