M9D Mantis Armour Defence System

"We're being pushed back during our reconnoitre, that Chieftain is screaming and yelling, then two Mantis mechs burst from the tree line, spitting high explosive shells and rockets, strutting around, stamping on shit. The Chieftain takes one to the head, and the Mantis walker just walks up to confirm the kill, then starts tea bagging the ape! I swear to God, I saw a giant mech teabag a brute!"

- Anonymous UNSC soldier