Stalker (species)
From Halopedia, the Halo wiki
The Stalker is a deleted Covenant species seen in the Halo 2 Collector's Edition DVD. Not much is known about this creature, but it is known about this alien is how they attacked; they would sneak up on their prey and tear it to pieces with their blade hands, similar yp the Flood Stalker Form.
It is worth noting that the Stalker looks quite similar to the Zergling of the Zerg race from the StarCraft series. The Stalker also has the same name and looks of the Pure Flood Stalker Form from Halo 3, and probably would have had a similar use in the Covenant if existed. These uses would include sneaking up behind enemies, and being scouts. Perhaps Bungie decided that the Covenant had enough races, and decided to add some more to the Flood. It may have been devastating to the UNSC if the Covenant had such a race.
