A very small demon doctor that comes to the human world to help treat Baby Beel and/or Hilda. She strongly disapproves of Oga and has recently been working with Furuichi to find Lord En.
Not much is known about her past except that Lamia has known Hilda, Forkas, and Beelzebub for a long time.
Lamia, who is created by Ryuhei Tamura, has no information regarding any inspiration used to create her. He first appears in Beelzebub volume 4 and episode 19. His Japanese voice actor is Kaori Fukuhara. Her name may have come from Greek mythology about a queen who eats children. However, the name does not reflect this Lamia.
It is assumed that Lamia has a tsundere personality with Oga. For example, she blushes and looks away when she is glad that Oga saves her in the demon world. She has kick Oga below the belt at least twice so far. For everyone else, she acts normally even with Furuichi.
She has bright pink hair and wears a red creature (MuuMuu) on her head. For attire, she wears a white, lab coat, dress shirt, a tie, a blue mini skirt, and striped socks. Like Hilda, she has green eyes.
*The rest shall go on the friends/enemies sections.
She appears with Forkas after Hilda has called them to treat Beelzebub's fever and when Oga comes home from his battle with Toujou. When Oga refuses to believe that Lamia is a doctor, Lamia kicks Oga under the belt. Forkas appear and smacks Lamia for acting superior. After Forkas explain to Oga that Beelzebub has a special fever and has severed the link to save him, Lamia is the one who administers the shot to Oga in order to have Oga reconnect his link with Beelzebub. 6 hours later, Lamia comments that Oga has failed, but Oga wakes up much to her surprise. Suddenly, Oga grabs Lamia and prepares to spank her. Yet, Hilda interrupts and asks Oga how he feel right now. Oga replies he is fine. The scene for Lamia's spanking is not shown afterwards.
After Oga has reconnect his link with Beelzebub, Lamia accompanies Hilda as they watch the battle between Oga and Toujou. She remarks that Oga is a bully since she still feels the pain from her spanking. When Oga wakes up Beelzebub and Beelzebub climbs on Oga's head, Lamia, Hilda, and Forkas are amazed about how close Oga and Beelzebub are and how the link attach so easily. During Oga's battle, Oga rejects Beelzebub's demon powers (his help) which makes Lamia angry at Oga. The following day, Forkas and Lamia search for Alaindelon as they prepare to head home to the demon world. After Hilda convinces Furuichi to call him, Alaindelon pops in. At the river where Oga first finds Beelzebub, Lamia gives a teary goodbye to Hilda and Beelzebub, and Forkas leaves first. Before Lamia can go home, Beelzebub latches onto her, and Oga and Furuichi pulls Beelzebub but fail. Lamia, Oga, Furuichi, and Beelzebub arrive in the demon world. As Lamia tells them that they are in the demon world, Oga hits a Yople alien which Lamia freaks out. According to Lamia, Yople are the friendliest demons, and in Vlad's hunt, is a dangerous place where poachers and demons exist.
Even she has no powers for attacking, she has her job as the assistant to Forkas. Her pistol administers the medicine to Oga by firing the shot on Oga's head.
The manga and the anime had some differences during the time where Lamia and her companions are in the demon world looking for Angelica. In the manga version only, there is still mysterious character who has a sword appears twice in front of Lamia and her friends. Also, the journey to Angelica's house (in the anime) has extra stuff that was not in the manga version such as the talking tree.
See episode 23 in the anime.