It's ok for a boy, a bit reminiscent of an old British man. I don't know why you would want to use it for a girl, it's a male name. MNS could be:
Basil MarkBasil AlexanderBasil ThomasFlip is ok as a nn for
Philip. As a full name, it's good only for a pet. Anaconda is horrible, it's a big snake, I do hope it's not her real name!