Can Rattata be shiny in Pokemon GO?

At the end of the Season of Mischief in Pokemon GO, trainers can catch a bunch of shiny Pokemon, including Rattata.

Is this a shiny rattata or what? : r/pokemongo

Pokémon Go' Update: Shiny Pidgey, Rattata, Start Time and Research Tasks

Shiny Rattata/Raticate (Alola Form) 6IV - Pokemon Sun/Moon US/UM Let's Go

Pokemon GO Spotlight: Can Alolan Rattata Be Shiny?

First Helper Shiny Rattata : r/PokemonSleep

Shiny Rattata

Pokemon Sleep: How to get shiny Pokemon - Charlie INTEL

Is there a Shiny Rattata in Pokemon Go? - Dexerto

Shiny Rattata

CALM DOWN!! SHINY RATTATA in POKÉMON LET'S GO PIKACHU AND EEVEE!

Mobile] Got my first Pokemon sleep shiny and I'm stoked! First shiny Rattata in any game!! :) : r/ShinyPokemon