It looks like the MCU was ready to give us a TON of big changes this month with the release of Black Widow and season finale of Loki because a minor character in Black Widow might have just been confirmed as the first mutant in the MCU!
Actor Olivier Richters recently confirmed on social media that his cameo appearance in Black Widow saw him playing the MCU's first confirmed mutant named Ursa Major.
Richters' character appears in the prison scene with Red Guardian and he is the large man who arm-wrestles with him and has his arm broken and according to the actor production on set secretly revealed who his character was during the filming of his scenes and it wasn't until now that he could share the news.
In the comics, Ursa Major is part of the Winter Guard (the Russian Avengers), which gets name-dropped and referenced throughout the film. Ursa has the power to transform into a Hulk-sized bear and in the comics has gone on to fight Wolverine and The Hulk.
While Richters doesn't take on the bear-form he can in the comics, Red Guardian does call him a "big bear" as he walks away, which could be Marvel Studios subtly planting seeds to pick up on later down the road.
You can see Richters post below and make sure you check out the latest episode of Crisis On Infinite Podcasts to learn about the OTHER BIG CHANGE coming to the MCU!