Scarab

Summary
The Scarab is different from most of the Covenant's other ground-based attack vehicles. Instead of using anti-gravity pods, it walks about on massive legs. It is highly mobile for a vehicle of it's size, and sports numerous turrets that shoot large shards of explosive crystals, as well as a massive, forward-firing plasma cannon.

The Scarab Gun is a weapon that players can pick up; it can be found on several of the levels where the scarab is encountered.

Images
http://img154.exs.cx/img154/9223/scarab0yk.jpg