Gigantamax (Not!) Umbreon .

Due to using the Last Rare Candy in Bag glitch (name tentative), players are able to force the in-game Gigantamax Eevee to evolve.
As you can in the screenshots, the 1st slot was the one that gained level, but the 2nd slot was the one that evolved.

While it will bear the Gigantamax symbol, there is no special Gigantamax form programmed for it;
it'll bear its standard Dynamax form when Dynamaxed in battle.

As this evolution was obtained using a glitch, it will be marked as illegal on PKHeX.

We bear no responsibility if you're banned for using this file, no matter how unlikely that is.