TV-Series
Description
The character known as the Démon de Dover in DAN DA DAN, also referred to as the Shrimp Alien or Mr. Mantis Shrimp, is a combat-type extraterrestrial whose design draws inspiration from the real-world Dover Demon cryptid of Massachusetts, the mantis shrimp, and the iconic Alien Baltan from the Ultraman series. Physically, he is a muscular, humanoid figure with a crustacean-like head, round beady eyes, and yellow-tinted skin. His typical attire consists of a pair of red boxing gloves, a necktie, and a speedo, giving him a bizarre but striking appearance. His speech is often marked by a distinct verbal tic, ending many of his sentences with the sound "dis".

His background is rooted in tragedy and a desperate struggle for survival. Hailing from an unspecified alien world, the Dover Demon was a weak member of his race who lost his wife to a rare, debilitating illness. This same disease is inherited by his only son, Chiquitita, causing the child to lose blood through his urine and feces, which necessitates constant blood transfusions. The Dover Demon's species does not bleed in the human sense; their blood is chemically similar to milk. To afford the expensive treatment for his son, the Dover Demon left his home planet to work as a gig worker or mercenary in dangerous sectors of space.

In terms of personality, the Dover Demon is a creature of necessity rather than malice. He is willing to follow orders from his employers, such as the Serpoians, but harbors a clear distaste for harsh treatment and poor working conditions, such as having his pay cut for poor performance. Despite his intimidating appearance and role as a villain, he has an oddly charming and quirky side, most notably his habit of humming or singing a parody of the ABBA song "Chiquitita" while engaged in combat. This juxtaposition of violent fighting and cheerful singing underscores the comedic yet heartfelt nature of his character.

The Dover Demon's primary motivation throughout his initial appearance is purely financial: to earn enough money to purchase the medical care and dairy cows needed to keep his son alive. This need leads him to be hired by the Serpoians as muscle during their arc. In this role, he serves as a significant physical antagonist, utilizing his immense punching power against the protagonists, Ken Takakura, Momo Ayase, and Aira Shiratori. His signature ability is the Jet Punch, a strike powerful enough to demolish buildings with a single blow. When underwater, his destructive power increases tenfold, allowing him to manipulate water currents for long-range attacks.

When the Serpoians inject him with a special energy drink, he undergoes a transformation known as Dover Demon Strong Style 24. In this state, his body becomes slimmer and taller, increasing to 1.8 meters in height while taking on visual traits of the Serpoians. This form multiplies his combat strength by a factor of 24, though it only lasts for 24 minutes.

The trajectory of his role in the story changes dramatically from foe to ally. After his defeat, he is taken in by Seiko Ayase, Momo’s grandmother. Despite Seiko initially beating him for lacking the dietary habits of a kappa, which she mistakes him for, she eventually learns of his plight. Realizing his milk-like blood matches his son’s needs, Seiko aids him in procuring dairy cows to serve as a blood source. Overwhelmed by this unexpected kindness from humans, the Dover Demon promises eternal loyalty, stating he will always be on their side before returning to his home planet. However, the environment of his world proves unsuitable for farming, forcing him to return to Earth. Disguised as a human under the name Peny, he works on a dairy farm and becomes a dependable ally, arriving at critical moments to assist Momo and her friends in battle, solidifying his status as the group's first alien ally. His development showcases a shift from a desperate mercenary to a grateful father and trusted friend.