James speaks of the tongue as if it were a wild animal. Here "tongue" represents a person's desire to speak evil thoughts. (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-metonymy]])
James speaks of the harm that people can cause by what they say as if the tongue were an evil and poisonous creature that can kill people. Alternate translation: "It is like a restless and evil creature, full of deadly poison" or "It is like a restless and evil creature that can kill people with its venom" (See: [[rc://en/ta/man/translate/figs-metaphor]])