Talk:Mershark/@comment-29564364-20170130200148/@comment-10429980-20170131031204

They're all fan-made characters based on various sub species detailed as end cards of the Monster Musume anime, the theme being that Bike Cop gets a harem of notably dangerous and hard to handle monsters who would otherwise get deported or arrested. They gained a fair bit of popularity thanks to a lot of nice fan art posted on 4chan and such but that was a while ago.