Which biblical figure was nicknamed "Boanerges" by Jesus?

The biblical figure nicknamed "Boanerges," which means "Sons of Thunder," is John. This nickname was given to him and his brother James by Jesus, indicating their fiery temperaments and zealous characters. In the context of biblical texts, this nickname helps to illustrate the passion and intensity they brought to their discipleship. While James is an important figure as well, it is John who is most commonly associated with this specific nickname in the narratives found in the New Testament, particularly in the Gospel of Mark. Thus, John is the correct choice for this question.