The Gitrog Monster is currently not legal in BO3 Historic, but is legal in Brawl, BO1 Historic, and the play queue
Gitrog Monster is now legal in Historic bo3 events, thank you! HOWEVER, it cannot be in a deck for direct challenges or bot matches. :(
Soren Feles#93349 commented
The Gitrog Monster is also unavailable in Direct Challenge. Even though the deck was marked Historic I was not allowed to use it. When I attempt to join a direct challenge or bot game with it it shows the number of Gitrog Monsters, and "Historic Deck. 2 Historic Cards in the deck", even though the amount of Historic cards is much higher. Direct Game option was not working either.
The Gitrog Monster is shown as being illegal in the Historic Bo3 queue, but it is legal in the Bo1 queue.
Dustin Jones#17012 commented
If you create a historic deck with Gitrog Monster it is not legal in Historic BO3 but it is legal in Historic BO1. It should be legal in both.