If you have ever played the first Borderlands game, then you surely remember Rakks. These flying creatures fly in groups and if disturbed, they will swoop down to attack you. They're not as common in this game, but can cause slight annoyances in the few areas you can encounter them, such as the area with the final boss in the main game. In the odd chance you encounter a Badass Rakk, be careful if it also has an element attached to it. They are quite weak, though, so they can be killed rather quickly.