The Echidna, once just a minning device, was adopted by the army to serve as an assault weapon. It is built with next generation materials, which are light weight but can take huge amounts of damage. The legs are used to climb difficult terrains, grab things or melee attacks. When in wheel mode, the Echidna can achieve speeds up to 260 km/h in open terrains. The huge wheel has other extra functions, it can inflict instant damage to other vehicles just like a giant chainsaw, it also helps to dig holes and destroy buildings. The Echidna can bury itself into the ground and serve as a temporal and small battle station, usually in groups of three or more vehicles.  

 

The Echidna: All terrain Vehicle. Part of a Speed Modeling Challenge at 3DTotal. Im not sure if the design can work in real life but anyway, here it is… 4 Hours modeling.