Sheruru was created in the same lab as most of the other Devil Fish Tribe members. Their lead project scientist, a newbie at the lab, had a lot riding on XZ103. It was the scientist's one shot at proving herself to the rest of her comerads. However, there was a problem, and of course, the project failed, not only because of Sheruru's appearance, but also at the seeming lack of any distict sexual organs. The scientist was demoted for her flop, but she still loved the little thing she had put her heart and soul into making. So, right before the small infant Sheruru was destroyed, she took them from the lab. Not knowing what to do with this creation, she kept the little hybrid in her home. She lived alone, so it wasn't too bad. There, Sheruru grew and learned. However their 'mother' found one of the child's favorite passtimes seemed to be slamming its head into a wall. However, when Sheruru was around the age of 6, the scientist was killed in a freak accident at the lab. When going through her home, Sheruru was discovered by the authorities and detained. But, using all their strength, XZ103 was able to headbutt the doors to the police wagon open and escaped into the countryside.
After a few days of wandering, Sheruru found the ocean, living there for the next while until one day they were caught sucking barnicles off of the underside of the Devil's Wrath. From then on, they lived happily ever after.
Sheruru is very much like a little fangirl. They are constantly trying to be the matchmaker to various people on the ship, regardless of the real feelings of the people being paired. The nautilus's opinion is often childish when it comes to this, such as trying to pair people based on similar physical or personality elements (Like Tumimi and Tanjuju both having claws, or Kanini and Kibaba both being sharks, etc.). Sheruru also indulges in making up fanfics (not really writing them) and drawing pictures of their pairing of the week. Along with this, they have also been stalking Kaii since joining, sometimes being his shadow, much to the oarfish's dismay.
Also, never drink the punch at the Devil Fish party. Sheruru will always spike it, usually with tequila.