The Colossus is a heavy tank-type javelin exo-suit.
The successor to the Javelin of Dawn, the Colossus is the largest of the four javelin types. It trades mobility for defense, carrying a deployable shield (along with reinforced armor plating), as well as a devastating Siege Cannon. A hulking war machine, the Colossus was designed to clear out entire hives of vicious predatory fauna with mounted artillery, heavy arms or even a flamethrower.  The Colossus model goes at least as far back as the time of the Legion of Dawn, and their leader, Helena Tarsis, who favored the use of the Colossus. 
Scars, particularly Enforcer colonies, pilot Flamethrower Colossus-class javelins. They seem to be incapable of retracting the shield, either due to a lack of knowledge on how to operate the Colossus's technology or just damaging the closing mechanism all together during the fight against the original pilots or during the acquisition of the javelin itself. They use it much more flexibly than the very Freelancers trained to use them, possessing the strength and accuracy to fire their flamethrower despite the shield always being up.
The Colossus is analogous to a 'tank' class,  trading mobility for extra firepower.  Slower than other javelin types, it is the only javelin which can be equipped with any of the heavy weapons such as a grenade launcher or autocannon.  It cannot be equipped with pistols or SMGs. 
Colossus as other javelins has its own special skills and gears.
- Ordnance launcher
- Heavy assault launcher
- Heavy support gear
- Heavy Smash (Melee) - Slam the ground with the Colossus’ two giant fists, dealing damage in an area around the mech 
- Siege Cannon (Ultimate) - Fire three giant missiles that explode in flames and cover a massive area. These are essentially three mini-nukes and deal high damage to single target enemies or large groups.  This makes it ideal for clearing out smaller enemies, controlling enemies in a choke point, or putting some extra damage on a boss. 
- Shield (Utility) - The Colossus raises its shield, allowing it to withstand attacks.  The shield takes damage when hit and cannot be used indefinitely.  The Colossus will be able to revive a downed ally even while the shield is active. In addition to protecting teammates, the shield can also be used while charging the enemy. 
- The Colossus cannot equip small weapons including pistols and SMGs.
- Haluk, a companion of the protagonist, pilots a custom-built Colossus javelin.
- ↑ Electronic Arts - YOU ARE A DESCENDENT OF THE LEGION OF DAWN IN ANTHEM
- ↑ Electronic Arts | THE FOUR JAVELINS OF ANTHEM
- ↑ Fandom - The Sci-Fi Epic that Sings Already: ‘Anthem’
- ↑ 4.0 4.1 https://www.ea.com/games/anthem/gameplay-features/colossus-javelin
- ↑ IGN - 19 MINUTES OF ANTHEM GAMEPLAY (WITH DEVELOPER COMMENTARY) IN 4K
- ↑ IGN - WE KNOW 135 MORE FACTS ABOUT ANTHEM
- ↑ 7.0 7.1 https://www.polygon.com/anthem-guide/2019/2/1/18204112/colossus-javelin-tips
- ↑ Electronic Arts - JAVELIN ULTIMATE ABILITIES IN ANTHEM
- ↑ YouTube - 4 Minutes of Anthem Open World Co-Op Exploration Gameplay - E3 2018
- ↑ IGN - ANTHEM: HANDS-ON GAMEPLAY AND EXPLORATION IMPRESSIONS
- ↑ Polygon - Class Abilities