Sensational Shapechangers of the 30th Century

Reep Daggle was the the son of R.H. Brandt, a wealthy businessman who sponsored the 30th century Legion of Super-Heroes. Born on the planet Durla-One, Brandt used his native ability as a shape-changer to become a human, in order to gain acceptance in human society which suspected his people due to their powers. However, a disease caused him to be stuck in human form for the rest of his life on Earth-One, as such he left his son to be raised by his other family until the lad came of age and has himself applied for the Legion as Chameleon Boy. Reep used both his form altering power and deductive mind for both the main Super-Heroes team and the Legion Espionage Squad. At one point, Daggle like his counterpart met the Hawkman of Earth-Two and even mimiced his form during a case where both battled Mordru and his minions. 

His counterpart in the 30th century of Earth-Two was foremost among the Defenders who had encountered various members of the 20th century Justice Society of America, although in his case he allied himself with Hawkman rather than oppose said member. As with his Earth-One twin Reep, this winged warrior was capable of flying and infiltrating into evil organizations in order to bring them to justice. Whether he himself was really a good Chameleon who unlike his fellow people decided to side with humanity is unknown although probable.

The Defenders were the main line of defense for Earth-Two while their Space Legion and Super-Police mostly monitored threats outside of their homeworld's atmosphere, although by no means alone. It was these Defenders who like the Legion of Substitute-Heroes of Earth-One were a second line of defense, albeit not always competent.

In addition to the Substitutes, there was Earth-One's Legion Academy which trained upcoming prospects for the original Legion, which were trained by Bouncing Boy and his wife Duplicate Girl.  There also was Earth-Two's Junior Federal Men, who followed in the footsteps of that era's preeminent Federal Man in Jor-L, who battled his femme fatale Nina-Q the Bandit Queen.