Blind Wolf

Blind Wolves were a species of eyeless predators found on Installation 04. Due to the loss of the Forerunners, it is not known whether the Blind Wolves evolved on a planet and moved the Halo installation, were specifically created by the Forerunners to survive on the ring, or evolved from a creature created by the Forerunners. At the same time, it is also unknown if they were or are existent on only Installation 04 or on the other Halo installations as well; assuming that they were somehow preserved in their original state as they would evolve separately otherwise on the other rings.

It is highly likely that they were used as a food source by The Flood. They may have even been used as a food source by The Covenant.

Possibly due to their blind nature or instead due to feeding on smaller organisms and thereby having some form of relatively passive nature, one could approach a Blind Wolf and mount it.

Unfortunately, due to the destruction of Installation 04, all known Blind Wolves were eradicated. Unless they also thrived on another Installation or very unlikely on whatever world they may have originated from, they are considered extinct.

Trivia

 * Blind Wolves were a deleted species that served as a form of vehicle and background organism in the original Halo game. It was removed because it was too hard for a player to control and its AI encoding was also too difficult to manage properly.