A thomil would attack a despoiler of the land with their stone fists by striking or enveloping them. They could change the shape of their limbs at will to best fit a situation, adopting hammers or sharpened points for their hands to harm their foes.
If faced with a dire threat a thomil could turn into a solid block of stone. While unable to attack or move in this form, the thomil was practically invulnerable to physical or magical harm.
Thomil were usually solitary creatures. A thomil could be petitioned to move by a wychlaran if a Rashemaar wished to mine in the area it was inhabiting. This was successful about half the time. Thomil protected sacred mountains and other sites in Rashemen in greater numbers.
Thomil were prevalent in Rashemaar folklore where they were both feared and revered since they not only protected Rashemen from enemies, but also punished Rashemaar who were too greedy and neglected to pay homage to the land. The thomil were sent, or summoned, to Rashemen in response to the rise of the Red Wizards in Thay.
Thomil presence in rock would radiate faint magic but it was otherwise indistinguishable. A thomil absorbed all of the sustenance it needed by consuming minerals from the land. The vast majority of their time was spent in a dormant state until they were needed.