Have you spotted a golden Magikarp in Pokemon GO yet?13
Players all over the world reported that they've been spotting a golden Magikarp in the wild, which was confirmed by Niantic in a blog post. It can also evolve into a shiny Gyarados, bearing the distinct red coloring it does in the old Pokemon games. The odds of coming across a shiny were not made public, but we have yet to come across one. Also, it's not clear whether or not the shiny Magikarp and Gyarados are event-specific, or they will continue to spawn after March 29, when the Water Festival ends.
Now, we have some bad news as well. While a lot of people have shown off their golden Magikarps, a growing number of players have reported that they caught a shiny fish, just for it to turn into a Ditto. So, in case that happens to you too, you're not alone.
No joke. I just caught a shiny Magikarp in #Pokémongo THEN it turned out to be a ditto. I feel vialated. And I can't prove a thing. !!!— Den i Mordechai (@denimordechai) March 23, 2017
Pokemon Go: 'goddammit, ditto, i wanted that magikarp'— Spooky Ghost Rat (@MorsRattus) March 23, 2017
Additionally, it appears that what could be a normal Magikarp for one user can turn out to be a shiny for another, so if you're hunting with friends, don't count on getting a golden Magikarp, just because your buddy got one from the same spawn.
In case you were lucky enough to come across a shiny Magikarp, do let us know. And if it was a Ditto, please accept our most sincere condolences.
source: Niantic via Pocket-Lint, Forbes