During one adventure in the 30th century, the Legion of Super-Heroes meet a Protean, a "protoplasmic" creature native to a planet in the Antares system. Proteans are simple but have intelligence, along with shape-shifting powers and limited telepathy. The Legionnaire called Chameleon Boy adopts him as a pet, naming him Proty. After Proty sacrifices his life to save Saturn Girl and Lightning Lad, Chameleon boy adopts another Protean as a new pet, naming him Proty II (though many just call him "Proty" as well). When the Legion of Super-Heroes later decides to challenge the villain Time Trapper, they recruit Superboy and the Legion of Substitute Heroes to join the effort. Nervous to leave their base unguarded, they have Superboy bring forth the Legion of Super-Pets to protect Legion HQ. Saturn Girl uses her telepathic powers to grants the animals their own limited telepathy so they can effectively communicate with each other and people. Proty II, left behind by Chameleon Boy, asks to join the team. After passing four challenges to show he can perform impressive feats even though his main power is shape-shifting, Proty II is officially welcomed into the LSP. Thanks to time travel technology, he is able to join the team on more adventures afterward.