Borderlands 3 has 5 Mayor's Killer Look Locations in Moxxi's Heist of the Handsome Jackpot DLC. They count as Crew Challenges (Collectibles) and are needed for the Killer Look trophy or achievement. They are also known as completing Mayor's Outfit (all Mayor Outfit Locations).

None of Mayor's Outfits are missable! You can still find all of them after the story in free roam. To see how many you found, press L3 / Left Stick on the world map and D-Pad Right to open the "Challenges" tab. On the world map, the ones you haven't found are marked by a green hat symbol and the ones you found have a blue (slightly transparent) icon. You can collect them in any order you like with any character you want. Go to their location and defeat the enemy that spawns there. Once you go near the locations, they get marked on your world map. Then you can place a waypoint on them to make them much easier to track down.