It is an inverted leg walking mech. Equipped with a 300mm Tesla cannon and light force fields, this personal walker was built for Deadpool to assist in capturing Wolverine. Reaching top speeds of 160mph, the Merc with a Mouth can keep up with almost any vehicle restricted to land (as well as most helicopters ;)
Note on LFX file:
A few pieces do not connect on the LDD as they do in real life. Extra wheels fit on plate side handle (Part 2540) pieces on the feet. As well as the two propellers. As for the large blocks with vents, the slip onto the plate 2x2 wheel holding(Part 4488) pieces via the webbing found by the inside studs. The minifig will also sit in the mech in real life, alas the LDD is lacking some build options.