The Bog Roosh is a mermaid-witch from the depths of the sea and she is the main antagonist in Hellboy: The Third Wish. She is said to be the oldest of all sea witches.
The Bog Roosh accepts to give three mermaid sisters a wish for each in exchange for the capture Hellboy. When Hellboy is lost at sea, the mermaids capture him and drive a nail into one of his horns that keeps him alive underwater, then they take Hellboy to the Bog Roosh's cave, where he is chained with the bones of Emile Bertrand, an old foe of Hellboy who pretended to be a wolfman to chaise little girls around and met his end when he fell of a cliff and his body ended in the sea where the Bog Roosh used his bones cursed with a great hatred for Hellboy to make a chain in order to avoid an escape.
When the sisters's task is completed, the Bog Roosh informs Hellboy what she will do to him but before that she starts granting the favors she promissed for Hellboy's capture. The first mermaid wishes to be reunited with her lover a merman hunter, who was set to find a great beast and hasnt appeared for many years, the Bog Roosh agrees to the wish but informs her that said lover is dead, then raises him as a zombie; he promptly attacks and kills the mermaid so they can be reunited in death. The second mermaid wishes for legs and lungs, so she can be united with the human she loves. The Bog Roosh grants this immediately; but since they're at the bottom of the ocean, the ex-mermaid drowns. The third mermaid wishes for a lost spear, so she can return it to the grave of her father. The Bog Roosh hands over the spear, and the mermaid safely swims away to deliver it.
The Bog Roosh then explains to Hellboy that she plans to kill him to prevent him from causing the apocalypse. However, the third mermaid sister, feeling remorse for capturing Hellboy, frees him. The Bog Roosh plans to torture her to death with shades of her dead sisters pulling her down, but Hellboy helps her. In the process, they discover the Bosg Roosh's treasure chamber where she keeps the souls of drowned sailors in jars - Davy Jones's locker. In the last fight with Hellboy, the Bog Roosh is killed, freeing the captured souls. As she dies, however, she passes her power on to the mermaid making her the new Bog Roosh as revenge. The mermaid frees Hellboys, planning to wait patiently for the end of the world with the ghost of her father.
PersonalityThe Bog Roosh has shown little care for the lives of others, she doesnt seem concerned if her wishes may couse their clients demise as long as her promisses are fullfilled. This may also indicate an unsafe and treacherous side or simply treating it as just business.
She is very vengeful, traitorous, manipulative, uncompromising, opprobrious, and sadistic, when the last remaining sister helped Hellboy escape she decides to punish her by bringing her sisters corpses to torture and kill her for braking her contract.
She is a very unhesitating and determined being doing anything in her power to capture Hellboy.
Powers and Abilities
While the extent of her powers arent shown completly, she has been seen to be able to grant wishes wich can do almost anything but they must be well made or they might have terrible consequences.
She is also able to reanimate corpses that do her biding and she seems to have control over sea creatures too.
She is also able to manipulate objects to create magic enhanced artifacts like the chains she made to restrain Hellboy.
At some point its explained that she hs the ability to forsee the future in dreams, while her efficecy is not fully explained, though she claims to be very exact.
Even with all her power she has one main flaw, she is not able to abandon the cave she lives in, thus explaining why she needs to rely to others to get what she wants at some extent.
While her main abilities rely on magic, when confronted with physical damage she doesn't seem to show grate endurance since she was ultimately defeated by a spear, winch was held by Hellboy who wasn't aware of her when she attacked him, making her death a casualty.