Sharik

Sharik is a mutt who grew up around the St. Aleksandr convent. He was given to Lada Kolova as a companion by Sister Evdokia, who feared that the girl would get lost in the woods while delivering the nun's message to her companions.
Sharik was not a well-trained dog, but he and Lada eventually found a way to work together, and he did help lead her to her friends. Subsequently, they arrived at the volkhv encampment, where the volkhvy took him away for safe keeping, while the party underwent a series of trials in nearby caves.
Sharik's age is indeterminate.