Mr. Dumont was played by Paul Bartel in the movie Piranha.
Biography
He was the one responsible for the summer camp at the river, where the children were enjoying their vacation. Together with Laura DIckinson and Betsy he was taking care of the children. He was not well liked there, not even by his subordinates. He ignored Paul Grogan's warning about the Piranha threat calling him an alcoholic.
When the children were in the river the next day, he is attacked by a piranha. After that he did everything to save as many children as possible, who were also under attack. He is guilt-ridden because of not having taken Paul Grogan's warning more seriously. It is implied he is finished as a leader of that place for what happened.