M29 Grizzly

The M29 "Grizzly" Infantry Fighting Vehicle was the standard "battle taxi" of Systems Alliance Marines for 20 years. However, while excellent in long-term planetary campaigns, the Grizzly's bulk and weight made it unsuitable for rapid deployment across the Alliance's expanding sphere of influence. As such, this led to the development of the M35 Mako, effectively phasing the Grizzly out.

A human vehicle similar to the Mako appears throughout the game, sporting a similar design, although it is lower to the ground and larger, with wheel covers and a different turret placement and design. According to The Art of Mass Effect this vehicle was an early concept for the Mako, but the developers didn't like how it performed in gameplay. They liked the look of it and kept it in the game as a static object. These are apparently old M29 Grizzly models, though the units are never named and no external markings can be found. The Grizzly is not drivable, and is never used (aside from as a stationary turret on Noveria).

The Grizzly can be found on various uncharted worlds, usually parked next to outposts (possibly as a rudimentary power source), discovered as wreckage, abandoned in their garages or stripped of necessary supplies. There are at least six on Feros - including two that have crashed into the tunnels and a few on the Prothean Skyway - and several on Noveria along the Aleutsk Valley that have been destroyed by the geth (and, in one case, actually crashed into Peak 15's garage door). It is likely that when the Alliance developed the Mako, they stripped down their Grizzly units and sold them cheaply to fledgling colonies or corporations as military surplus, although some still retain their armaments. Despite their poor capabilities in planetary exploration, mercenaries and "wildcat" miners sometimes use them for such purposes, often with bad results.