- The Arachnosaur and Chaosteros are aliens in the IDW portion of the Generation One Continuity family.
During his sojourn on LV-117, Wheelie encountered several species of deadly fauna in the area.
The arachnosaur appears to be a giant spider-like creature, with eight legs and seven eyes, dwelling under the sand to strike at prey. Wheelie encountered it after triggering its web tripwire, and was saved only by its accidental puncturing of his energon converter shocking it into retreat. Its fang, however, remained embedded in the converter, forcing repairs.
The chaosteros is a colossal reptillian creature, covered in a mane of quills or spines, and is apparently the planet's most deadly animal. After ambushing Wheelie, it tore off and devoured his left arm, though it passed undigested through its system, allowing Wheelie to recover it later from a steaming pile of whatsit. Eww.
- The design and name of the chaosteros appear to reference Chaos, the titular beast of the cartoon episode Chaos.