Arcateenian

The Butterfly People are a race of glowing humanoids from the planet Arcateen 5.

Biology
Physically, the Butterfly People are tall humanoids, whose bones and internal organs show faintly through their skin. They have tendril "hair" on the top of their head and on their backs. They have five long, slender fingers and have a blue tint to their skin. (TW: Greeks Bearing Gifts, SJA: Invasion of the Bane)

Mary, a Butterfly Person, was shown to have super-speed and strength, telepathy and the ability to inhabit the body of a Human. (TW: Greeks Bearing Gifts)


 * Whether all Butterfly People have these abilities or whether these abilities were technology based is unknown.

Technology
The Butterfly People have faster-than-light travel capabilities, including transporter systems and superluminal communications technology. (TW: Greeks Bearing Gifts, SJA: Invasion of the Bane). They had developed this by at the latest the early 1800s. (TW: Greeks Bearing Gifts)


 * Sarah Jane Smith's friend, the star poet, however did not seem to use a transporter, but when leaving simply flew away into the night sky.

History
In the early 1800s, a criminal Butterfly Person was sent to Earth from Arcateen 5 with her jailer. She killed the jailer and took over the body of a passing Human. She continued to live on Earth for 200 years by feeding on the hearts of other humans. According to her, at that point in time Arcateen 5 was run by an oppressive government which forced worship and exiled prisoners like herself. (TW: Greeks Bearing Gifts


 * Mary may have been lying about Arcateen 5's history.

By the 21st century, there appeared to be a more benevolent government on Arcateen 5, and peaceful star poets from the planet would travel to other star systems with their poetry. One such traveler met Sarah Jane Smith and gave her a superluminal communications device. (SJA: Invasion of the Bane)