Niantic has announced that Feebas can be encountered during the Limited Research Day which takes place on January 19th or 20th, 2019, depending on your region of the world.

Discover more with Limited Research, featuring Feebas!

Trainers, It’s time to put your research skills to work and collect Field Research that looks closely at a certain Pokémon species -- let’s do some Limited Research! While the Water-type Pokémon Feebas may not look like much, there’s plenty to learn about the Fish Pokémon! Spin the Photo Disc at nearby PokéStops to obtain Field Research tasks that lead to encounters with Feebas. And, if you’re lucky, you just might find a Shiny Feebas! See more details below:

Event Date + Time

• Europe, the Middle East, Africa, and India: Jan. 19, 2019, from 10:00 a.m. to 1:00 p.m. UTC (GMT +0)
• The Americas and Greenland: Jan. 19, 2019, from 11:00 a.m. to 2:00 p.m. PST (GMT −8)
• Asia-Pacific: Jan. 20, 2019, from 12:00 p.m. to 3:00 p.m. JST (GMT +9)

Features

• Limited Research tasks will be available when you spin Photo Discs at PokéStops.
• Completing the Limited Research tasks will reward you with encounters with Feebas.
• You may encounter a Shiny Feebas!

Feebas migrate quickly during Limited Research, so exploring is key! As long as you’ve collected the Limited Research during the event window, you can complete it at any time. Don’t forget: you’ll need to venture onward to many PokéStops in order to get new Field Research tasks and encounter as many Feebas as possible!

Source: https://pokemongolive.com/post/fieldresearch-jan2019