Dryads are plant-like humanoids. Gnarl referred to a dryad as a "plant-person".
Biology and Traits
All dryads seem to be connected to a central pod, which allows them to regenerate and recover from any damage they may have taken. It is not unusual to see several dryads linked to a single pod, sometimes even as many a four. While the dryads are unharmed and mobile, the pod is virtually indestructible. On the other hand, as long the pod remains, dryads will continue to regenerate and never truly die.
All dryads that are connected to a pod must be temporarily defeated before the pod can be destroyed. While the dryads recover, the pod will open, allowing the Overlord and his minions to attack the core and take out the dryads once and for all.
As both dryad and pod are made of easily combustible materials, Reds are ideal for fighting them, especially if they happen to be in a field of dry grass.
You can attack a Dryad and knock her health down to zero, but it will not kill the Dryad. She will just regenerate for a little bit and then start fighting again. You must destroy the pod to which the Dryad is connected in order to kill the Dryad. You can only attack the pod when it is open and it will only open when the Dryad is regenerating. There may be multiple Dryads connected to a single pod. You must knock out all of them for the pod to open. If one of the Dryads recovers, the pod will close again.