Deer and deer-like creatures

Deer are ungulate mammals of the taxonomic family Cervidae. While deer are indigenous to Earth, both deer and deer-like creatures have been discovered by the United Nations Space Command on at least one Halo ring—Installation 07.

History
Both deer and deer-like creatures were among those preserved by the Librarian against the firing of the Halo Array in 97,445 BCE. Following this destructive event deer were reintroduced to Earth and both they and similar creatures were seeded upon at least one Halo ring. Following the discovery of Installation 07 by respected scientist Doctor Luther Mann just as 2555 was dawning, a form of deer-like creature was encountered by and befriended by Mann once he had joined the Unified Earth Government initiative concerned with studying and occupying the ring.

Anatomy, physiology, and behavior
The deer-like creature befriended by Doctor Mann on Zeta Halo was small and named "Vanessa" by him, despite his inability to conclusively determine its sex. Every morning around the same time, Vanessa would show up around the same time and stare at him expectantly until he fed her with lettuce, which she chowed down enthusiastically. Satisfied with the food, she would them take several steps forward so that Mann could rub her under the chin. This elicited a noise from Vanessa that sounded vaguely like the equivalent of a purr.

Behind the scenes
Falcon's Creative Group was tasked with recreating its own versions of the so-called "space deer" first featured in the 2018 trailer for Halo Infinite. This was done so that they might be featured within "The Ring Experience" at Halo: Outpost Discovery. According to Jason Ambler, executive producer of the experience, the deer were primarily based on moose but were given their own unique sorts of antlers. 343 Industries reportedly wished for various creatures seen on the Halo ring in the experience to look as if they belonged on Earth but possess some features which made them look slightly alien as well.

List of appearances

 * i love bees
 * Halo: Hunters in the Dark
 * Halo: Outpost Discovery
 * Halo: Point of Light
 * Halo Infinite