I found this feature in the first couple of issues of the DC Comics title TOMAHAWK. It's as mediocre as all the other half-page humor features DC used to run, but I assume it's the only one ever centered upon a female Real American. For a time, TOMAHAWK included not only stories of the titular Indian-fighter, but also backup strips about Indian culture.
"LOW ALLOMYTHICITY-- This would apply largely to what I've " called a "monster of the month" situation. Godzilla faces a number of one-shot monster-opponents-- Ebirah, Megaguirus, Biolante-- and although they are allomythic in comparison to Godzilla, their stories end in their debut tales, and so they do not sustain their allomyths beyond a low level of intensity." -- ALLOMYTHS, pt. 2.
As I've looked over the various entries I've made since starting this project, I see that I've tended to emphasize three types of monster-mash. The first emphasizes a group of monsters who occupy superordinate status, what I've called Primes. The second deals with a group of monsters who occupy subordinate status, what I've called Subs. (An interstitial category involves both groups in opposition to one another, as in the TV cartoon DRAK PACK.) The third opposes two monsters from separate franchises, as seen in FREDDY VS. JASON and ALIEN VS. PREDATOR. In the essay quoted above, though, I did account for the existence of a low level of allomythicity in simple one-on-one conflicts between monsters, usually where one of the freakazoids (Godzilla, Gamera) is the star of a series. Yet I've also devoted posts to one-off encounters of two disparate monsters like "Full Moon," wherein the two opposed monsters not only don't generate franchises or histories beyond their generic identity; they don't even have proper names. Surely, even if a Godzilla-foe like Biolante only has one go-round with the Big G, just being part of Godzilla's gallery of grotesques earns him more mythicity than a one-off vampire and werewolf. At this time, I don't know that I'll start posting that many more examples of monster mashes comprised of just a continuing mon-star and a one-shot enemy, if only because there are so many of them. But I'll probably start working in a few just for consistency's sake. ADDENDUM: This post invalidates my statements in the first two "anti-mashup" posts that a couple of one-shot encounters, respectively in the "Gamera" and "It the Living Colossus" serials, were not true "monster mashups."