That was a great story, it feels kind of corny, which must be a sign of me becoming older, but I like how all the characters interact with each other and like how you made them use their nonhuman characteristics in efficient ways. Most people tend to forget about things like tails all together, but here you use them as part of the characters' arsenal and quirks. What I like most of all is the transformations of the characters, despite it being more pleasurable than I expected, which made it enjoyable and I really like the tail growths for each character.
Although I was surprised that Hooper was turned into an eel even though it is logical, it's just that I thought he was going to turn into a robot dog or merge with it instead. But his transformation did make the final parts more exciting and I was surprised that this is the official "reveal episode" of this series. Also, when Hooper was going to show off his robot dogs I seriously thought that he might get into a small argument from a couple of spectators because his F1D0 extremely resembles Blade Wolf of Metal Gear Rising. I mean seriously, almost everything you written about F1D0, is reminiscent of that character even his moves are like this guy:
So I seriously doubt you made the robot dog without it being based off of Rising's version and if you did that is seriously some strange coincidence. Anyway great job on the story.