A potion to cheat death... almost.
Argaiv Silaic, a wise, excentrical explorer and physician, once discovered the blue mushroom's secret, and had a chance to note what he found out.
Woodrats - In a fantasy realm of cooshee (elven dogs/cats) it is to be expected that there is some sort of elven vermin. These mercurial rats are lightning quick, and are capable of hiding in plain sight. Other than this, they have no special ability.