Chameleon Men

The Chameleon Men were a group of shapeshifting aliens who knocked out and replaced the Legion of Super-Heroes during Supergirl's visit from 1962. They then locked Supergirl and Whizzy in the Phantom Zone. However, Supergirl and Whizzy escaped and imprisoned them. ("Supergirl's Greatest Challenge!")

Due to their similar abilities, and the term "Chameleon Men", these may be an early form of, or a precursor to, the Durlans, the race to which Chameleon Man is a member.