Teenage Mutant Ninja Turtles easter egg
Patricia Tannis will give you a quest called "Splinter Group". The first step is to pick up some "bait" from Mad Moxxi, which is actually pizza. Patricia will say after you pick it up that they love the stuff. You end up going into the sewers, which then is a hideout of the runaway mutants. Leave the pizza on the table and get ready to fight four "brothers" who talk like the TMNT turtles. After defeating them, you will go further and can choose to just leave and forget about the puzzle in the final room, or try to complete the puzzle to turn five red lights into five green lights. Once all lights are green another mutant will will come out of hiding and attack you. All five of these mutants does flips, rolls, and jumps just like a ninja would do.