Boat Ear Mask is a Black Cross Army Masked Monster. His main weapon is a paddle-like staff he can use for long-distance attacks. However his secret weapon is his "Ear Hell", involving two long ribbons branching out from his massive ears to capture and strangle a victim. He also can spit out poison darts from his mouth. Further if his huge ears are chopped off, he can reform them on his staff into an axe-like weapon.
Boat Ear Mask's mission involves the pursuit and capture of a scientist set up to be protected by the Gorenger who has learned the secrets of "Minus Energy", which can be used to make a supremely-powerful bomb for killing humanity. The Gorenger try to protect him by leaving him with Asuka, but Boat Ear Mask and several Zolders trick him into a car, where they attack and wound Midorenger while hurting the scientist before taking him hostage. Using a mind machine, Boat Ear Mask tries to draw out the secrets within but Kaijo and Peggy save him with the Masked Monster in pursuit. Ultimately Aorenger and Kirenger show up to save their protected target with Variblune, allowing the team to take on the Masked Monster. Asuka returns with blades attached to his Midoranger to slice off Boat Ear Mask's massive ears in order to prevent him from using his Ear Hell, but he merely reattaches them to his staff. But before he can use it in combat, he is destroyed by Gorenger Storm.