In author Jack London's The Call of the Wild, the Yeehat tribe considers Buck the "Evil Spirit" because he killed many of them. When Buck returned from one of his hunts in the forest, he found the Yeehats celebrating in his camp. They had killed the other dogs as well as Pete and Hans and most notably, John Thornton. Realizing this, Buck attacked them with ferocity, ripping out the throat of the chief and causing some of the Yeehats to kill one another, in the chaos of trying to shoot Buck with their arrows. Finally, they ran into the woods with Buck in hot pursuit, destroying as many of them as he could.

After that day, the Yeehats called Buck the Evil Spirit and were afraid and in awe of him. They noticed him leading the pack of wolves--this ghost dog who some had lost their lives to when they killed the one person he loved above all others--John Thornton.

Why do the Yeehats consider Buck an evil spirit in Call of the Wild?

When Buck returns to the camp to find the Yeehats dancing around the shattered mine site, the rage that possesses him is overwhelming. As London writes that "for the last time in his life [Buck] allowed passion to usurp cunning and reason." Buck goes absolutely wild and his ferocity is astonishing to the Yeehat.

Buck attacks them and moves about so quickly that when the Yeehat try to shoot arrows at him, they end up shooting their friends. One man even throws a spear to hit him and ends up killing another man. They've never seen an animal like this before and when they finally run away they are convinced that it must have been an evil spirit because no animal could do what Buck did.