No, you cannot catch a shiny version of Gimmighoul in Pokemon GO, as it has not been added to the game yet.
Gimmighoul only arrived in Pokemon GO on February 27, 2023, and Niantic doesn’t usually add a shiny form of a new Pokemon when it releases.
However, if it’s a super-rare shiny Pokemon you’re after, then you may be interested in a new Research Story. The Pokemon GO Masterwork Research: Wish Granted gives you a guaranteed shiny Jirachi!
Also, if you haven’t caught a Gimmighoul yet, you’ll need to connect Pokemon GO to Pokemon Scarlet and Violet. Then, the process of catching Gimmighoul in Pokemon GO is pretty simple!

When Will Shiny Gimmighoul Come to Pokemon GO?
Pokemon GO developer Niantic has not announced when the shiny version of Gimmighoul will arrive in the game just yet.
However, we think it will be well over a year before we see a shiny Gimmighoul in Pokemon GO. This is because there isn’t a shiny Gimmighoul in Pokemon Scarlet and Violet either.
However, there is a possibility that shiny Gimmighoul could arrive in the new Pokemon Scarlet and Violet DLC, The Hidden Treasure of Area Zero!

Can You Catch Shiny Gholdengo in Pokemon GO?
No, you cannot catch a shiny version of Gholdengo in Pokemon GO.
This is because you cannot catch a shiny Gimmighoul in the game, and the only way to get Gholdengo is by evolving Gimmighoul using 999 Gimmighoul coins.
Find out every way to earn Gimmighoul Coins in Pokemon GO. This will speed up the process of evolving Gimmighoul into Gholdengo!