SO, I watched this in the aerly 2000’s, before 2010, definetly.
I watched it on TV, maybe on a channel called 7mo Vicio or Septimo Vicio (They would usually show shorts and talk about weird, under, indie movies).
The short ocurred in a city, and was about a kid that would be outside, playing with other kids (maybe), then would go near a pond (maybe the other kids forced him? he did seen a little of a pushover), and a fish-like creature, black, maybe a little bit eel-ish, would jump into him, the kid’s eyes turned black. He would grow extremely shy, not talking to many people, even when he wanted to; I concluded that it was because of the fish that had infected him.
Later the kid, now a young man, would wanted to talk to a young lady he fancied, so he walked up to her while she was working. She worked in a fish shop (fish market?) and she would try to talk to the guy, who didn’t answered her (maybe because of the fish inside him). Then the kid barfed the fish, the girl smiled at him nervously, grabbed a knife and cut the fish’s head. The guy’s eyes returned to normal, I believe.
I don’t remember if it was with and black or colored, but because of the type of film it was it wouldn’t surprise me that the colors were a little different than normal colors (maybe more monochrome? maybe even b&w, idk).
I’m not sure if tit was French or not. I’m under the impression that it was, but it could have not been.
I also don’t remember if there was any dialogue, in any case, I can’t tell if it was in the original language or dubbed to Spanish (or subtitled).
I think it gave me the sensation of being anxious, because the fish would be controlling the man to issolate himself even when he didn’t want, until the ene when he threw up and the fish scaped.
I watched it on the TV when I was a kid, as I said, and I would love to find it again. Once more, the important items I rememebr the best: kid, black fish, infects the kid, black eyes. Kid grows, goes to a lady, spits the fish, lady cuts it, young man is free.