D&D Monsters: Mummies

The concept of the mummy as an undead monster is really a 20th-century invention, beginning with the 1932 horror movie The Mummy. While mummies and immortal Ancient Egyptians had featured in earlier fiction, they were not really in the form we're familiar with now, or that formed the basis for the D&D monster, and still don't date back any further than the mid-19th century. Since their 1932 debut, however, they have appeared in a number of older-style horror films, and become something of a cliche, if not quite as popular as werewolves and vampires.

In D&D, they are mid-powered undead, falling into what I've termed the "wilful corporeal" category, given that they retain sentience and intelligence alongside their physical body. Under that scheme, they would fall somewhere between a wight and vampire in terms of power, but they are quite different from both. The look of a mummy does not, of course, change notably between editions; they are bandage-wrapped mummified corpses, sometimes dressed in funereal finery, but more usually not. Like most D&D undead (except vampires) depictions of females are rare, although not quite to the extent that is true of, say, ghouls or wights.

D&D Monsters: Giant and Phase Spiders

The first edition of AD&D includes a number of giant invertebrates, mostly insects. The idea behind these may be influenced by the "big bug" films of the post-WWII era, starting with Them! in 1954, and they provide the possibility of exotic-looking monsters that nonetheless have to look no further than the natural world for inspiration. 

Once we leave insects and look at spiders, there is an even more obvious inspiration: Shelob in Lord of the Rings. While she, and her relatives in other Tolkien works, were likely the primary inspiration behind the original giant spiders of D&D, there are plenty of other fictional examples. The cinematic classic The Giant Spider Invasion is one such (yes, I've actually seen it; there's 80+ minutes of my life I'm not getting back...) and, from more modern fiction, there's Aragog in the Harry Potter books. Giant spiders aren't found in European myth, but there are the Tsuchi-gumo of Japan, which are usually described as spiders (but sometimes crickets) and, at a stretch, Anansi the spider-god of West Africa.