The Scorchies had no physical form after their planet was destroyed, so they took the form of puppets to attract viewers to their show.
The Scorchies was a given name to the species. They originated from a planet that had only recently discovered television by Professor Baffle. A species came along and destroyed the planet through television. Professor Baffle then tried to save his people, but they ended up as formless, floating between planets. Taking their revenge on the universe, they burned out planets by hypnotising the population through their TV show. They earned their name because of this. The Third Doctor and Jo Grant encountered them on Earth, eventually defeating them and sending their consciousnesses back into space. (AUDIO: The Scorchies)