This kit includes parts to assemble a complete "riddler's mech".
"You forget, you bothersome, Bat. Every time you overcome my puzzles I learn that little bit more about you. Soon enough there will be a riddle that leaves you dead!"
Edward Nygma, the Riddler has been trying to beat and the destroy the Batman for a long time. During the events of Arkham Knight, Batman beat Nygma's tests to free Catwoman and discovered / solved all of the riddles around Gotham. The Riddler came back one more time armed with a giant mechanical exo-suit.
In the Batman Miniature Game, Mech Riddler is a Leader for the Riddler crew. At 123 Reputation he is deadly with a Mechanic Claw, Laser Beam Cannon and ability to make his own Bots explode on command. The Mech even protects him with an inbuilt Energy Field.