In spite of many glaring inaccuracies and inconsistencies with the established "Star Trek" canon, these four Aliens sold well-enough to warrant a third (and, as it would turn out, final) series of "Trek" figures, consisting of four more Aliens: a Romulan, a Talosian, an Andorian, and a Mugato. These four figures are counted among the rarest of Mego's produced figures, due in no small part to a fire at a Mego facility which, as the legend maintains, consumed a large portion of the third series' stock. The fact that the word "legend" is used in this instance is a testament to the stature of these four figures and the fascination that surrounds their manufacture and relative scarcity; when you talk about series three, you're not so much relating history as you are delving into action figure folklore. These final Aliens rank up there with Alter Egos, Teen Titans, and Space: 1999, a fact borne out by the prices they consistently command. Regardless of any warehouse disasters, this series of figures would still have been in high demand today if only for two reasons: the Romulan and the Andorian, two Aliens whose canonical accuracy and innate style almost make up for the glaring deficiencies present in the other six.
Mego, for reasons unknown, created new card art for these figures as well. Actually, "recreated" is probably a more apt term, since they closely patterned the new design on the previous one, making only slight changes. The new card art still depicted essentially the same planetary landscape, but it differed in several important respects: firstly, the "sky" was changed from black to blue; secondly, the stars were all-but-removed; thirdly, the card maintained the width of the previous card design, but was now noticeably taller; and fourthly, the card back now featured all fourteen of the "Star Trek" figures, while simultaneously eliminating half of the accessories advertised on the previous package to make room for the profile expansion. In addition to releasing the final four Aliens on these new cards, Mego took the trouble to re-release the previous series of Aliens on the new card art as well. This fact could be attributed to a desire for uniformity on Mego's part, if it were not so painfully obvious from almost all other evidence that uniformity was pretty low on Mego's list of priorities.
The eight-inch line of "Star Trek" figures effectively died with these last four Aliens; so, too, did every Trekkie's dreams of a Harry Mudd or a Khan, a Sulu or a Chekov, a Nurse Chapel or a Yeoman Rand. It would be left to the Mego customizers, a generation later, to pick up the ball that Mego dropped in 1976.