Somthing I made really quickly
That's a Sped, a Self-Propelled Explosive Detta. Essentially, it's a bomb, the chassis is reshaped to carry as much explosive charge as possible. It's mostly empty cavity that Ven fills with as much of whatever explosive he can mix up in his manufacturing bays with the materials on hand. Therefore, it's impossible to know exaclty what yield a SPED is carrying. It could carry anything from a full millitary-yield warhead to some kitchen-sink chemical explosives.