As an aside to what others have already pointed out about “braaaiiiiinss” originating in Return of the Living Dead, the zombies in that film also aren’t mindless. They can still think and feel, and they crave brains because it (somehow) eases the pain they feel from their bodies decaying.
It’s an element of zombie lore that I really wish was used more often because it makes becoming a zombie even more frightening. They’re also totally immortal beyond cremation, so no aiming for the head to put them out of their misery.
The first and third Return of the Living Dead movies are my favourite zombie films ever. The second is… fine. It’s basically a remake of the first focused more on comedy like Evil Dead 2, but it didn’t really work for me. The two latest movies throw out all of the unique elements of the series to become generic zombie movies and aren’t worth watching.