This is an example of what happens when random rolls, Gygaxian naturalism and OSR goodness get mixed within the recesses of my imagination. Awhile back, a simple random wilderness encounter turned into the Blighted Fist orc tribe (itself a randomly generated name). Playing off this name, I decided to give these orcs a special weapon — clay pots full of Rot Grub. In prepping for my players' most recent foray into the wilderness, I rolled up an encounter with a dragon in the same territory occupied by the Blighted Fist. In my mind, these two random encounters ought to be related somehow. . . it's that fuzzy warm place in my mind where I actualize my own distorted version of Gygaxian naturalism.
When I get a series of random encounters that share the same space, I like to try and link them via an ecology that makes sense — somehow, whether biologically or socially, these creatures have a relationship. Contemplating the disparate encounters of orcs and dragons, two things formed the foundation for this relational ecology. The first was a nice little post by Dyson Logos over at A Character for Every Game where he re-skinned some dragons with a variety of cool concepts. The second was a comment on a post at Grognardia musing on purple worms that postulated the cool factor of purple worms being the larval stage of dragons. The link between these two was the lowly Rot Grub.
I decided to steal Dyson's idea of the Carrion Dragon since it fit nicely with the Rot Grub theme. Imagining that the Rot Grub is a kind of (very nasty) egg, I added this wrinkle: 1 in 6 Rot Grubs won't go for the heart, but rather for the stomach. When they come into contact with the stomach acid, they start to produce a chemical that serves two purposes: 1) it starts a metamorphic process that will result in the larval stage 2) it causes the adrenal gland in the victim to go into overdrive.The result is the victim is driven mad/transformed into a berserker. Riffing off the Carrion Dragon, the larval stage is the Carrion Crawler. The overactive adrenal gland serves two purposes — it protects the egg in its initial metamorphosis, and it eventually leads to the death of the host giving the small Carrion Crawler its first meal.
The Blighted Fist enters the picture as willing hosts to the Carrion Dragon's eggs. The orcs see the dragon as a kind of avatar bearing divine gifts that transforms worthy recipients into uber-orcs. As such, they have become a bunch of zealous fanatics dedicated to the care, feeding and harvesting of the Rot Grub eggs and their Carrion Crawler hatchlings. These uber-orcs are created during ceremonies in which Rot Grubs that are most likely to go to the stomach instead of the heart are chosen and placed onto the stomach of those orcs undergoing the "transformation." If the wrong Rot Grub is chosen, the victim orc was "not worthy." Those who receive the eggs successfully are transformed into a berserker class of orcs. Upon their death a small 1HD version of the carrion crawler will eat its way out of the corpse in 1d12 hours. The Blighted Fists shower their enemies with Rot Grubs in order to feed enough so that they are ready to go into the stomach of a willing orc.
In turn, when the carrion crawlers have engorged themselves enough on rotting flesh, they will form a cocoon. Eventually, a young carrion dragon will emerge. Upon reaching adulthood, these dragons will start producing Rot Grub and the whole process begins again.
6 hours ago