Me and a group of friends have recently grown attached to the concept of a Dorf, all thanks to the antics of mine and many other forts. Then problem arose when wanting to create an equally zany origin story for these dorfs when implemented in a DnD setting, but after much deliberation we have reached this conclusion: Beard Parasite!
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The life cycle of this beard-looking parasite is little known. What we DO know is that the little critter's life cycle depend on copious amounts of ethanol theorized to stave off other potential pathological compromises to it's host as the parasite itself does not have a high resiliency and the host is usually either dead or dying.
On the matter of hosts, the beard parasite has only been observed attaching itself to large rocks, or wayward gnomes, taking on the appearance of excessive facial hair in both cases. It is theorized that the host determines the gender of the dorf, rock hosts make one, and gnome hosts make the other, but it is impossible to distinguish once the host is taken. The parasite upon attachment also makes the host more irritable, illogical, dim-witted, and possibly murderous.
The beard parasite reproduces by means of spores, and thusly cannot reproduce as easily in cramped quarters, making the host desire larger areas of habitation, preferably with decorations as decorations are shiny and likely to attract the attention of the host's impeded mental capacity. This urge also drives the host to construct large vertical structures as the updrafts and downdrafts generated by these constructs help in the spreading of spores.
The climate preference of the parasite is warm and damp, this is imposed upon the host in more extreme climates by the urge to go several hundred feet underground. At times when a magma vent is found, there is conflict between host and parasite, while the host itself will have the urge to flee, the parasite will want to stay and be warm. Internally the conflict rages like that of an elf who was offered adamantine in a wooden crate, but outwardly the conflict is a stalemate even in cases of the host catching fire.
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That's all we've managed to come up with so far, opinions? Additions?