dragon parasites

Returning to the realm of 'real' biology for a moment, let's talk parasites... Parasitism is ubiquitous, with some sort of parasite evolved to exploit a host species.  Parasites range from fungus, plants, single-celled organisms, worms, arthropods, and even a few vertebrates.

Most parasitic relationships are commensal, where the host is not significantly harmed or aided. Some are antagonistic, with the host harmed, and some are symbiotic, with the host and parasite both gaining value.

So, it stands that dragons must have parasites. And like dragons, they will be odd and perhaps unpredictable.

Dragon Louses

For this exercise, I'm using eight dragon age categories - ranging from Very Young to Ancient.

For a dragon of any particular age range, there is a 5% chance that they have become exposed to parasites, either via another dragon, or through another vector. For our S&W dragons, this translates to a 5-40% chance that an individual dragon is parasitized (in reality, the chance of parasitism of an organism is greater, but dragons are magical, resistant beasties...).

Conversely, older specimens are less susceptible to side effects from parasites, and the likelihood of a parasite directly affecting an infected dragon will be 100%-(5% per age category); e.g. an ancient dragon will have a 100%-40% = 60% chance of a direct parasite effect.  Effects will be determined by the table, below. Effects from the parasitic infection may be positive, negative, or (since this is S&W), odd...

Parasite Effect Table

Roll d8 & d4 - first is column, second is row

	D8/D4	Effect	1	2	3	4
	1-3	None	No Effect	No Effect	No Effect	No Effect
	4-5	Positive	Increased breath damage (increase die by one*)	One additional attack/ round or increase damage by one die	Faster movement (+5% per age category)	Additional breath weapon use (+1/day)
	6-7	Negative	Decreased breath damage (decrease die by one)	One less attack/ round or decrease damage by one die	Slowed movement (-5% per age category)	Decreased breath weapon use (-1/day)
	8	Odd	Random breath	Random breath 2	Breath weapon of another dragon, random	Dragon mind control

* - i.e. d6 to d8, reverse for decreased die 

Depending on the parasite biology, parasites may be passed by exposure during mating, melee or post-mortem butchering/trophy-taking.

Dormant eggs or cysts may be carried by a host creature, with a bite or consuming by a dragon required to hatch the organism.