In Gregor the Overlander, Vikus is Luxa's grandfather and the husband of Solovet, making him one of the few alive relatives and family of Luxa.
He is one of the first ones to believe that Gregor is the warrior from the prophecy of Gray.
Vikus is generally kind and peaceful. He helps Gregor full fill the prophecy, and persuades his friend, Ripred the gnawer, to join the quest.
Like all underlanders, Vikus is probably pale and has violet eyes. He is described as having grey hair, and is a tall old man.
He is very wise, but holds back many of his thoughts if he thinks the person receiving them might not be able to hold it and handle it well.
Because of this reason, Luxa and Gregor had doubted him for some time in the stories.