Meet Sea Strike :3
 
She is a shark pony, trained to become a solider that specialises in aquatic warfare.
 
She was abandoned as a baby, found at sea by a bunch of sailors out late at night, who took her home to their village, where they raised her. They developed a habit of biting and wrecking things a lot as a child, which was a pain (figuratively and literally) for everyone XD  
Despite her wild nature, she would receive an education and learned how to adapt to normal pony life.
 
One day as an adult, her village became under attack by a group of pirates, which she was able to help fend off. upon hearing the news, a branch of the Equestria Military contacted her, as asked if she would like to become part of the team. She said yes, and after a few years of training, she became a full part of the team.
 
She is part of an Underwater Demo Team (UDT), which specialises in stealth, explosives, and underwater/aquatic warfare. She puts her massive strength and sharp teeth to good use.
 
Sae Strike is a cocky mare and one to not take things as seriously as she should, but she is still a loyal mare to her team and friends, and she is very protective of others. Currently dating another mare in the special forces, Shadow Stalk.