In the mission "Splinter Group" the four mutated raiders that you must kill are named "Mick, Lee, Ralph, and Dan" this is a play off of the Teenage Mutant Ninja Turtles named "Michelangelo, Leonardo, Raphael, and Donatello". The other similarities include: their hideout being in the sewers, their name "Splinter Group" , along with a hidden Easter Egg found later in their lair of an enemy named "Flinter", after the rat master "Splinter", their surfer like language ("dude", "brah") and their craving for pizza used to lure them out.