I see no description at all of what a harpoon gun is. It's not something primarily used by Esmé.
These omissions are so great that the article's factual accuracy has been compromised. Check out the discussion page and revision history for further clues about what needs to be updated in this article.
Harpoon guns are weapons which shoot long, pointed, spear-like arrows upon the trigger being pulled. In A Series of Unfortunate Events, the Harpoon Gun was used by Esmé Squalor[statement unclear] to shoot down Hector's self-sustaining hot air mobile home and, in the Netflix series, by Jacquelyn, a member of V.F.D., to threaten Count Olaf aboard the Prospero.