12 Marvel Characters You Didn't Notice Are Already In The MCU

In Black Widow, Natasha Romanoff teams up with her step-sister, Yelena Belovna, to break their stepdad, Alexei Shostakov, out of a maximum security prison in Russia. While they make their way to the facility, Alexei is arm-wrestling with prisoners, while spinning a yarn about how he fought Captain America.

When a hulking inmate accuses Alexei of telling porkies, the superpowered Russki slams his opponent's arm into the table, shattering his wrist. The scene is brief, but it's a nice moment since it demonstrates Alexei still possesses superhuman strength, despite looking less than physically ideal.

But this sequence has a hidden detail few people picked up on during their first viewing. After the inmate questions the accuracy of Alexei's claims, he says, "Are you calling me a liar, Ursa?"

With that simple exchange, Alexei confirmed his opponent was Ursa Major - a super Soviet who can transform into a 7ft tall bear (which makes you wonder why he's freezing his ass in a prison in the middle of nowhere).

Because Ursa Major is a mutant, this marks the first time a mutant has appeared in the MCU.