Three youths with fantastic powers, Lightning Lad, Cosmic Boy, and Saturn Girl, save billionaire R.J. Brande, who bankrolls them in an organization meant to emulate Superboy and Supergirl, the Legion of Super-Heroes. The three get themselves snazzy new outfits, select a leader and create a constitution. Triplicate Girl and Phantom Girl are the next to join.
Superboy [Clark Kent]; Lana Lang, Jonathan Kent; Martha Kent; Legion of Super-Heroes [Lightning Lad; Cosmic Boy; Saturn Girl]; Phantom Zone inhabitants [Jax-Ur; General Zod; Mon-El]; Legion of Super-Pets [Krypto; Streaky; Super-Monkey; Super-Horse]; Brain-Globes of Rambat; Superboy Robots
Superboy is attacked by his friends in the Legion, under the evil influence of the Brain-Globes of Rambat. After the Legionnaires regain their senses, they gather four super-pets to defeat the Brain-Globes. The Legionnaires officially name them the Legion of Super-Pets, an animal branch of the the Legion of Super-Heroes.