Protos

Protos is a small moon orbiting Methuselah near the galactic core. Orbitally locked 'behind' the larger planet, Protos only sees brief moments of sunrise, many years apart. It is a cobalt-colored world with corrosive gases, raging seas of nucleon that mutate mechanical life, showers of shrapnel-like ice needles, and caustic windstorms. Protos is the most inhospitable environment imaginable, cloaked in near-absolute darkness, locked in the shadow of a giant planet that shields it from view. Few know it exists, even fewer have visited.
Fiction
The Transformers cartoon

Protos served as Primacron's lab, where he created Unicron and Tornedron. Call of the Primitives Ask Vector Prime
3H comics
Protos was created by Primus billions of years ago as a prototype and dry run for the creation of Cybertron. For 300,000 years, part of Primus's essence reshaped Protos from the inside out, creating a self-sufficient hive-like colony, Sanctuary, and then creating life, the first 12 Transformers. Covenant
Animated cartoon
Primacron had a lab on Protos, which was located deep within Vok Territory. The AllSpark Almanac II
TransTech
In the wake of the descending of the Shroud, TransTech Minister of Higher Dimensional Sciences Rhinox proposed to create a Large Pulsar Array in the vicinity of Protos to create a Hyperwave dimensional-oscillation generator in order to restore Axiom Nexus's transdimensional capabilities. Ask Vector Prime

