Who is the second person killed by the monster in the novel Frankenstein?

The second person killed by the monster in Mary Shelley’s novel Frankenstein is Henry Clerval. The creature murders Victor Frankenstein’s closest friend as an act of revenge after Victor destroys the unfinished female companion he had promised to create.

Earlier in the novel, the creature kills William Frankenstein, Victor’s young brother, near Geneva. Justine Moritz is then executed after being falsely blamed for William’s death, but the creature does not kill her directly. Henry is therefore the monster’s second direct human victim in the novel’s sequence of murders.

Victor discovers Henry’s body after reaching the Irish coast, where he has been arrested and accused of the crime. The shock causes Victor to suffer a severe mental collapse. Henry’s death also turns the conflict into a personal vendetta: the creature has already warned Victor that he will be with him on his wedding night, a threat later fulfilled through Elizabeth Lavenza.