Crannak was bald - his hair frequently burned off in fires of his own creation. His left arm ended in a stump, to which he had attached an iron prosthetic of a clenched fist.
Crannak was a pyromaniac whose only desire was to see everything on fire. In his rare lucid moments he demonstrated a manipulative cunning, placing his devoted apprentices in between himself and sources of danger, fleeing if he felt overmatched.
He was seen cackling maniacally in the presence of fire.
At one point, Crannak was caught in a fire that severely burned the left half of his body - leaving him blind in one eye and severely mutilating his hand.
His devotion to the destructive power of fire led to him joining the Cult of Eternal Flame and quickly ascending that group's ranks. His skills in smithing gained him five devoted apprentices who called themselves 'Burn Punchers' (after they burned off their own hands in molten iron to emulate their master's injuries), and the commission to build the Hateforged Hellion - though the Cult was forced to place guards on Crannak while he worked for fear of him running off to indulge his fiery whims.
Crannak was noted to have possessed a healing ember, and sometimes carried unstable magical smoke bombs. He set fires and used his magic in battle but also carried a dagger.