After the Chameleons left Earth, they passed Krennos shortly afterwards and decided to kidnap and impersonate its humanoid visitors. After taking their place, the transformed Chameleons would return to their victims' homes for a while to avert suspicion from Krennos, then return to the Chameleon's home world. The Doctor discovered their plan and put a stop to it.
In addition to their spacecraft and space station, the Chameleons also had electric guns, laser cannons, and paralysing devices. The process used to assume the identities of Humans involved the use of armband-like devices placed on both subjects. If an armband was removed from the original, the Chameleon that assumed their identity would be killed, reduced to a small blob of protoplasm. The abducted Humans were miniaturised and placed in suspended animation.