Harmonigan (ハモニガン Hamonigan?) is a kaiju that appeared in episode 24 of Fireman.
- Height: 48 m
- Weight: 10,000 tons
Harmonigan was a monster created from the vengance of a harmonica which had been thrown away. It emerged in Yume no Shima, causing nightly noise and earthquake every evening. It managed to absorb Fireman's Fire Flash. It emits flames and heat rays from holes on the body and manipulates countless instruments like limbs. It was blown as a harmonica by Fireman until its anger died out and it returned to its normal harmonica form.