The Stalker is a concepted Covenant species seen in the Halo 2 Collector's Edition DVD. They attacked by sneaking up on their prey and tear it to pieces with their blade hands, similar to the Flood Stalker Form.
Deleted Material[edit source]
While developing the Halo games, Bungie, 343 Industries and Ensemble Studios have had to cut some content, such as vehicles, gameplay, and story elements, from the final products. Much of this content has been confirmed by videos and commentary in special edition DVDs, interviews with developers, and released concept art.