Velmoc flu was a disease that originated on the world of Velmor. It seemed to be connected in some way to the indigenous Velmoc species of that planet. Once someone recovered from this illness, they would develop a resistance, preventing them from contracting Velmoc flu again. During his time away from his home on Tantajoc V, Prince Denid became infected with this disease, but ultimately overcame it. Upon his return to Velmor, Chozz Wardle, the royal doctor, documented that Denid had recovered from the illness, which served as additional evidence to verify Denid's claim as the rightful heir to the throne.