Of Love, Scales, & Fins by orphan_account
Rating: E Status: 16/16 Chapters Word Count: 74,455 Creator Chose Not To Use Archive Warnings
Katsuki Bakugou is doing what he can to rise up in the ranks as a criminal, even if it is wasn't his first choice in life. Of course, he made the mistake of messing with the Shie Hassaikai clan, which landed him in the river to swim with the fishes. Or, at least that's what he thought. The last thing he remembers before waking on the riverbank is a beautiful face & a soft kiss. Then, the same man, whom he thought was just a figment of his imagination, shows up at his door, naked aside from his neighbor's garments & telling Katsuki that he's a member of the merfolk! What the fuck?
my notes: oughh i love mer aus SO much and this one was so cool!! warning for angst later on, but it has a happy ending if you're worried about that. in this one katsuki is saved by mer!izuku after pissing off the rival gang, and then of course mer izuku gives up his legs in hopes of katsuki one day loving him back. but, there's a catch- katsuki has to SAY 'i love you' to izuku within a month, otherwise izuku will turn into a hideous monster (his TRUE mer form) forever and then katsuki will NEVER love him. ... right?
it has some side ships that are ALSO a joy to read, but it's got feral izuku, teen!kirishima, gang boss enji (i actually really like how he's written in this one, and i don't like enji much in canon with where i'm at, but i know a LOT of spoilers lol.), adorable eri and shinsou (aged down to be closer to eri in age i believe, and yes! they got adopted by erasermic!).
remember to read the tags on ao3, be respectful and always follow the golden rule of fic: don't like, don't read.