Dreg

In a possible timeline, Dregs were the mutated remains of those surviving humans who were left behind following a catastrophic war on Earth, now designated Orphan 55. Unlike their human ancestors, Dregs required carbon dioxide to breathe and exhaled oxygen as waste.

These creatures were highly adaptive, able to survive the nuclear winter of Orphan 55, the low O₂, high CO₂ atmosphere of the planet and various forms of weaponry used by the Tranquility Spa staff to repel them, which required them to use randomisers on their laser blasters in order for their weapons to remain effective. (TV: Orphan 55)