Sorry for the fact I don’t have a scanner. Have some biology.  
Behemoth: Originally created as a tool for path clearing, a Behemoth now serves as a weapon of mass destruction.  
Hive workers would pile their dead, from as many as five to fifty,and the Queen re-animates the biomass into, quite literally, a walking tank. The Behemoth possesses no flying abilities, but makes up for it with incredible strength, size and speed.  
Behemoths took part in the Invasion of Canterlot, however the were not able to scale the giant mountain and thus left the airborne troops to do the work. Had they been able to reach the shield Canterlot would have been destroyed with many casualties.
 
PS. This is headcanon. Not OC.