Count Oömfumf is the Spark who causes (or at least contributes to) the avalanche and smashed railway bridge that stops the Wyrm of Limerick while Agatha is on board en route to Paris. He uses sound as a weapon, and is fighting with Count Wolkerstorfer to see which of them will capture Margarella Selnikov, who is also a passenger on the train. He is killed by Count Wolkerstorfer who uses a death ray on Oömfumf, burning him to a crisp and melting his "one-man band" apparatus of musical weapons.