During the Credits
Other than a faint Gears logo in the top left corner, there are no extras during the credits of Gears of War 4.
After the Credits
There is a stinger after the credits of Gears of War 4 that reveals the fate of one of the main characters.
In the extra scene, Oscar Diaz is shown cutting himself out of a Snatcher. Once he gets up and wipes himself off, he says, “So… uh… where the hell is everybody?”