One of the more adorable (and human?) scenes in the latest Captain Marvel trailer was Samuel L. Jackson's Nick Fury going gaga for a feline. There isn't much in the way of info on who owns the cat or why it seemingly was on what appeared to be some kind of operation with Carol, but if this cat is who many THINK it is, things might get a bit interesting.
During the most recent iteration of the Captain Marvel comics (circa 2014), readers were introduced to the truth about Chewie, Carol's pet cat. Chewie isn't a cat; Chewie's a Flerken. It was actually Rocket Raccoon who told Carol about the creature she possessed. Flerkens look like Earth cats and act like cats, but have a number of different abilities, ranging from storing entire universes in their mouths to tendrils being housed in their mouths (which can attack at will) to the ability do travel across dimensions.
Now, that's not to say that this cat is the Chewie we know in the comic books, or that this cat is a Flerken. But what if it is? Assuming this cat survives the '90s and is by Carol's side in the current MCU timeline, that's a powerful creature to have in your arsenal battling a being like Thanos. Hell, Rocket survived The Snap; recreating that sequence from the comics in Avengers 4 feels too easy.