Nerida was created by Poseidon. It was an accident, and it wasn’t meant to happen, but it did. Poseidon was just playing around, showing off with some tricks when he accidentally made a nymph, and that nymph was Nerida. Nerida was beautiful, and so the friends of Poseidon immediately asked for her hand in marriage, thinking it was part of the show. Poseidon, stunned because he had made this creature, declined them all and decided to adopt and train Nerida-at least until she could take care of herself.
For fifteen years Poseidon had trained Nerida in his court. Nerida grew up to be strong and healthy, and attracting all kinds of attention. Poseidon thought Nerida wouldn’t be attracted by monsters, seeing that she was just an innocent nymph, but he was wrong. He sent her for some quests sometimes, and would always be surprised by the stunts she did. When Nerida was around twenty, a random monster just bounced out of the woods. That something was a myrmeke-if Nerida wasn't mistaken. She drew her Celestial Bronze dagger out from her sheath-a gift from her "father", Poseidon, just in case-and looked at the giant ant. The myrmeke clicked its mandibles and Nerida, without a doubt, knew it was calling for backup. Nerida quickly realized the ant was after her dagger-they loved shiny things, after all-so she threw it as far as she could, hoping to distract it. The dagger landed in a nearby river with a big SPLASH.
Nerida smirked. She had made a perfect plan by accident.
During her monster studies, Nerida knew that myrmekes were afraid of the water, and she could also control water, being a water nymph. She ran to the river with the myrmeke hot on her trail, and several other giant ants joined the parade. By the time Nerida reached the river, she was winded, but she kept her focus. She swam to the other side of the river, retrieving her dagger along the way, and crawled out of the river. She smiled at the myrmekes. "Come and get me! This free snack only for sale today!" Nerida taunted. She waved her bronze dagger for extra effect, and when the ants were seriously getting hungry and annoyed by this creature, they came nearer to the river, and one even jumped into the water. Nerida concentrated, and felt a tugging feeling, and a huge wave of water came crashing down on the myrmekes. Nerida started to pass out, but before she did, she sent a telepathic message to her friend Aqua, another sea nymph(yes, sea nymphs can do that) and told her "HELP!!!".
When Aqua told His Royal Majesty, Poseidon personally found Nerida passed out, and when he heard her story, he decided she was going to be fine at Camp Half-Blood. Nerida is still new there, not being there for more that two weeks, but she has already gained respect and trust and made friends. She helps with bringing demigods to camp as well, and she's okay with the life she has now.