The Blood Beetle is a parasitic insect that inhabits all known land masses. This insect typically attaches itself to large animals, such as hadrosaurs or boars in order to drink their blood. It does so by clamping onto them with its massive jaws and claws and using its mandibles to bite into the skin of the host. The means by which it stays on the host animal make it incredibly painful to remove by force, which leaves the afflicted creatures stuck with this pest for a long time.

The only time this beetle willingly detaches itself from the host is for breeding purposes, which occurs when multiple parasites infest a single animal. These bugs will then mate and produce egg sacks that will fall off onto the ground, ideally into the host's droppings.

Blood Beetles have a preference for the largest animals since that provides them with more food, and causes the negative effects of their blood drainage to be less noticeable...and the benefits more notable.
The Beetles are covered with a very hard, spiky carapace, the main purpose of which is to make it harder for the host animal to scratch them off and to prevent most parasite-eaters from predating on them. But that carapace also has a slight benefit for the host, by providing armor. While a single beetle's effects are negligible at best, a whole swarm of them is a different story.
To explain it in "game terminology"
- Each parasite reduces the maximum HP of the host animal by 2 points
- In return, the parasite's carapace increases the host's defense by 2 points
- This effect stacks with each subsequent beetle attacked

There are certain creatures that the Blood Beetles avoid parasitizing. Those include:
-True Dragons;
- Fey-touched creatures.
The working theory is that the highly mana-charged blood of these creatures is somehow repelling the beetles. Some push this theory even further by stating that mana-charged blood might be toxic to the beetles. Further observations and effects on other types of creatures are yet to be made.