From: Adventure Comics #322, plus Adventure Comics #320, Superman #170, and Superman Annual #1 (May-July 1964)
In "The Super-Tests of the Super-Pets" we don't exactly find out how a dog, a cat, a monkey and a horse who used to be a centaur learned to work together, because this story from Adventure Comics #322 is basically about much they DON'T want to let anything else join the Legion of Super-Pets. Xenophobia is so rampant here, it's hard to believe it comes from an organization that features four (maybe five) different species.
It all begins when the Legion prepares to go fight the Time Trapper and have to leave someone in charge of defending the Earth. That's to be the LSP, and Proty, Chameleon Boy's blobby "pet", after being denied the possibility of going on the trip, tries to join the interim team. His application isn't well received.
In case you're wondering, that tribunal-type furniture wasn't just for the cover to mimic the famous "let's troll Superboy" cover of Adventure Comics #247; it's actually in the story. Superboy built it, likely for just this purpose. First the Supet-Pets tell Proty he needs super-powers to join, and he has that! He can shape-shift! But it's not good enough for them. He needs to pass each of their tests, each one more difficult and ridiculous than the last. Since we're only interested in Krypto, let us just gloss over the others, but you tell me if they're fair.
-Comet: Proty must impersonate Superboy (he doesn't gain his powers) and accept his next mission whatever it is (Proty has to go to another planet and recover some important crystals).
-Streaky: Proty must fool Saturn Girl, a telepath, while impersonating another Legionnaire.
-Super-Monkey: Proty must prevent the Legionnaires from entering the club-house for a whole hour (even though this is a state of emergency with everyone preparing for temporal war).
Proty succeeds every step of the way, and nobody hits any of the Super-Pets with a rolled-up newspaper for screwing with him. One test left. Krypto's. And here's a clue as to how that'll go.
Now don't count your Proteans before they're sludged; if you haven't figured it out by now, this is a story about trolling. Trolling Proty (who must then troll the Legion), and trolling the reader. In Krypto's test, Proty must track him and capture him, even though he has the unfair advantage of super-speed.
He's hiding in Niagara Falls, Proty! Turning into a salmon, he finds him, but Krypto escapes, and then makes a fatal mistake.
So it's more a matter of saving the dog's life at this point. So how do we get to that splash panel from here?
Of course. We were dealing with a shape-shifter and a style of storytelling that doesn't play fair with the audience. And that's how the Super-Pets BEGRUDGINGLY let Proty into the team. I guess they had to. Really going to screw up their red cape motif though...
Around this same time... in Adventure Comics #320, Superboy remembers the fun he had with his pup and a robot dog when he was a child.
...in Superman #170, Lex Luthor takes Jor-El's place on Krypton and is annoyed by Krypto's father who could smell the evil on him.
...and hey, forgot this one back in 1960: Superman Annual #1, where we got a reprint of Superboy #67's "The Execution of Krypto".
Still scored a bit of cover real estate out of it.
Comments
At any rate, the Legion of Super-Pets strikes me as a group I'd rather not join, tho' it may be that the high standard set by the original Proty was in the back of the group's minds when they decided to test his successor, though a quick perusal of the original story (it's free online, at readcomiconline.to) doesn't seem to mention Proty I.