mystery fish
mystery fish is another word for a gross vagina. Its any girl that has been around and possibly contracted an std. You have no clue where she has been or who she has been with, therefore she could be called "mystery fish"
"Dude, Amber has been around so much, im changing her name in my phone to mystery fish"
Large Mysterious Fish eats a Duck
A Youtube video that shows a lake with ducks swimming in it, and then suddenly a skeleton jumps up in front of the camera with the same scream as K-fee and scares the viewer.
Me and my friend watched Large Mysterious Fish eats a Duck and now we can't sleep.