The Legion of Super-Pets make their official debut in Adventure Comics #293 (Dec 1961). The Legion of Super-Heroes recruit a variety of super-powered pets: Krypto, Streaky, Beppo and Comet the Super-Horse, who makes his “sneak peak” premier here.
The pets are called upon to save Superboy and the Legion of Super-Heroes who are being threatened by the Brain-Globes of Rambat. Naturally the Brain-Globes cannot control their minds because the super-pets are just animals… who… do have minds…