Two bandit characters that look similar to Rick and Morty from the Rick And Morty TV show will appear in Lectra City, Promethea. This is a completely optional area. They usually spawn in the Underpass area. If you wait around long enough on Sanctuary III, you may get lucky and the "Kill Wick & Warty" side mission will appear. Start the quest, and a waypoint will mark their location on the Lectra City map. Track them down and defeat them for a chance at a random Legendary weapon dropping. A Legendary weapon commonly drops after defeating them.