From Halopedia, the Halo wiki
UNSC Armed Forces
The M808B3 Tarantula is a a modified variant of the M808B Scorpion main battle tank.
The Tarantula is fitted with twin Scimitar 40x178mm hypervelocity rocket pods.
Tarantula models were employed during the Human-Covenant War. Due to their ineffectiveness against Covenant forces, most models were re-equipped as regular M808Bs.