Solonian
The Solonians were a race with several different forms, shown in The Mutants. As their planet, Solos, went through its seasons, the Solonians gradually mutated into the next form. This naturally occurred with radiation and a special green crystal from the planet. These changes can also be artificially caused by pollution.
Humanoid Solonians
The Humanoid Solonians were the form which existed during the spring of Solos. They appear to be dark-haired humans. The main difference from humans was their ability to breathe the poisonous mists of Solos. They were at a low level of technology when they were discovered, with a simple farming and hunting culture.
Sometime in the 25th century, the human empire from Earth discovered Solos and started to exploit it. The Solonians were taken advantage of and their planet was stripped of its resources. By the 30th century, tensions were rising and the mutations from the modified atmosphere were starting to increase.
Insectoid Solonians
The Insectoid Solonians (pejoratively known as Mutts to the human overlords) were the intermediate form from the start of summer on Solos (something like a mobile pupa). These Mutts were a bit shorter then humans and covered in a thick black exoskeleton. They have a head, thorax and abdomen, as well as clawed arms and legs. They have bulging yellow eyes, a wide opening for a mouth and long pincers beside their mouths. Insectoids seem to have decreased intelligence and cannot speak, though this could just be because of the transformation. They have no central nervous system and are cold blooded.
Near the beginning of summer, the Humanoid Solonians are supposed to have an unusual instinct to seek out the necessary radiation and crystals for the transformation. This instinct is something like voices in their head, compelling them to search out the radiation. Though the Solonians are supposed to mutate into this form with radiation and crystals from certain caves, the changes can be brought on early with pollution. Unnatural changes can leave the victims confused and uncertain about the entire process.
- During the events of The Brain of Morbius (which was not dated), a ship piloted by a creature with a strong resemblance to an Insectoid Solonian crash-landed on Karn. This race was known to Dr. Mehendri Solon (no relation) and was unfazed by their apparent space-faring capabilities. This might imply that some Solonians somehow didn't reach the next stage and instead took to the stars (but see below).
Advanced Solonians
The Advanced Solonians were the form which existed during the summer of Solos. The insectoid Solonians are transformed into advanced Solonians by more radiation. Though they had the basic shape of a human, advanced Solonians are almost angel-like, with a robed body and scintillating colours. They communicate telepathically and have a wide variety of powers, including the ability to pass through solid matter and to shoot energy beams.
Behind the Scenes
A Mutant costume was cosmetically altered and reused to represent a generic insectoid alien for the opening scenes of The Brain of Morbius, but the production team did not intend to suggest they were the same species any more than in the case of the Axons and the Krynoid (another case of a recycled costume). The novelisation of the story makes it clear that the creature belongs to an entirely different species.
