None of us realised at the time, but it turns out the woman next to Michael B. Jordan's Killmonger in the first Black Panther trailer is actually supposed to be Tilda Johnson, AKA Nightshade.
Actress Nabiyah Be has been cast in the role, and her sister recently confirmed her character's identity in the Tweet below.
In the comics, Nightshade (formerly Dr. Nightshade and Deadly Nightshade) is a genius-level supervillain who first debuted back in the '70s and has faced-off against the likes of Captain America, Luke Cage, Iron Fist, and, of course, Black Panther over the years.
Johnson probably won't have a huge part to play in this movie, but there's always a chance the character can be expanded upon in future MCU instalments. Watch out for those werewolves, guys!