Theodore Sturgeon's story, "It," first published in 1940, tells the tale of the once-wealthy Roger Kirk, who died in 1929. Gradually, the plants and elements of the earth gathered around his skeleton and become a semi-living thing-- and the foreshambler of a monster that has lurked in the dark places of popular culture ever since.
It did not take long for a comic book to plagiarize and popularize the concept.
In December 1942, the third issue of Air Fighter Comics (Later Airboy), a title dedicated to adventuring pilots and flying aces, took a turn for the bizarre. Harry Stein and Mort Leav told the horrific (and, to readers of Sturgeon, familiar) tale of Baron von Emmelman, a German fighter pilot shot down in 1918 over Wassau Swamp in Poland. Emmelman did not die; rather, over the years, he transformed into a humanoid mound of swampy matter, and crawled out from his apparent grave. It needed flesh to survive, and often consumed animals. Its human opponents might be from either side of the Second World War, but it was the Axis, invariably, who suffered most. The creature did not have heaps of intelligence and it lacked the Baron's memories, but it had a simplified personality of its own.
Although intended as a one-shot character, the Heap reappeared and in 1946 Airboy made it the star of a regular feature, the misunderstood monster for whom the title became best-known. Later, the Heap received his own series. The anti-comics crusade of the 1950s came down particularly hard on Horror Comics, and Hillman Comics ceased publishing the character, and then their comics, by the middle of the decade.
When the influence of the Comics Code Authority waned in the early 1970s, another company, Skywald, began publishing stories about the Heap. Skywald never formally acquired the rights, and its Heap differed in some ways from the original. In 1986, Eclipse Comics purchased several old Hillman properties, and began issuing new, legitimate adventures of the animated vegetable. In the 1990s, Image took over the rights and set a revised version against their star, Spawn. This Heap was formerly Eddie Becket, a street person transformed after he found a supernatural substance.
The Heap has had many imitators, who owe at least as much to it as to Sturgeon's original character. DC comics introduced a Heap/Frankenstein Monster named Solomon Grundy in the October 1944 issue of All-American Comics (#61). He remains a part of the DC Universe, his variable strength pitted against many different superheroes. Over at Marvel Comics, The Hulk carries more than a little of the Heap in his irradiated soul. Marvel, in fact, has a thing for hulking monsters, and heaps of them have lurched through its history. Even closer to the source come DC's Swamp Thing and Marvel's Man-Thing, both introduced in 1971. In 1972, Marvel directly adapted Theodore Sturgeon's "It." Mad Magazine #5 (June-July 1953) featured a story called "Outer Sanctum," which parodied Inner Sanctum, EC's own horror comics, and the Heap. Dungeons and Dragons, meanwhile, features the Shambling mound among its many monstrosities.
The Heap may have stolen its life from a pulpy Sturgeon story, and many no longer know it by its most famous name, but its mucky matter has been integrated with the broader culture. Likely, it will continue to shamble on in our nightmares.