The Grizzly is protected by thick armor plating which allows it to survive even the fiercest attacks and features dual M310 120mm Smooth-Bore High-Velocity Cannons mounted in its turret. These cannons can easily punch a hole through almost any Covenant vehicle and fire S1 canister shells to decimate infantry formations. A co-axially mounted M247T Medium Machine Gun gives it additional firepower. Smoke grenades were mounted near the turret.
The Grizzly first entered service in 2509. Grizzlies were used to great effect during the Liberation of Harvest, and the UNSC Spirit of Fire contained a robust inventory of M850s during the extraordinary events of 2531. After the war, the 23rd Armored Cavalry was outfitted with a complement of M850s in addition to their primary force of M808s. The Grizzly tanks were used by the UNSC Army at the Battle of Draetheus V against the Covenant Remnant.
In the Campaign, the Grizzly is available during the level Relic Interior. In Skirmish and Multiplayer, it is available after completely upgrading the Scorpion when Sergeant Forge is selected as the player's hero unit. Once it has been researched, it can be purchased at the Vehicle Depot.
The Grizzly is an extremely capable vehicle, capable of defeating large numbers of enemy troops and vehicles. Since it possesses a secondary canister shell attack, it can crush infantry with ease due to its large blast radius. The armor plating has also been improved, able to absorb multiple shots from a Hunter's assault cannon, and can survive a sustained hit from a Scarab's main weapon twice as long as a Scorpion. The coaxial machine gun has a faster firing rate and inflicts more damage per hit than the Scorpion's, at the cost of a longer reload time. Its main disadvantages is the cost it requires to be researched, its reduced effectiveness against other vehicles and its ineffectiveness against airborne units; it is also extremely slow because of its increased weaponry and armour. As with the Scorpion, it is "hard countered" in-game by Cobras, especially while they are in lockdown mode.
- Resources: 1800 (upgrade for Scorpion) 500 (for individual unit).
- Minimum Tech Level: 4 (upgrade for Scorpion) 2 (for individual unit once researched).
- Population Count: 3
- Originally, the Grizzly was stated to be equipped with a Flamethrower, but this was removed from the final game.
- In Halo Wars, a 14 star Grizzly is strong enough to take down a Scarab. It is also enough to survive multiple MAC Blasts.
- Ironically, a group of over 3 Grizzlies will lose to a group of the same amount of Power Turret Scorpions due to the fact that it takes 4 Scorpion canister shells to destroy one Grizzly whereas a Scorpion can survive over 10 Grizzly canister shells. Grizzly canister shells deal the same amount of damage but spread it out over a larger area.