Haney and Cardy spin a story in Teen Titans 2 (March/April 1966) that sees the team deal with a couple of teenage caveboys, frozen until the present day. Though neither of these characters appear again, the concept would return later in the run, with the introduction of Gnarrk.
This story, which also briefly shows the Titans Lair, their hangout, has Robin, Aqualad, Kid Flash and Wonder Girl called in to help Garn, a fairly normal looking blond boy, who is trying to integrate into modern society, but who is being menaced by his old caveboy enemy Akkuru
It's Akkuru who s going on destructive rampages, but Garn is getting the blame. The whole story is fairly ridiculous. We are meant to believe that Garn thawed out and just went on to try to join society really quickly, and though the other kids tease him, no one was particularly blown away by having a caveman now living among them.
Garn has a girlfriend who believes in him, and who is the one to call on the Titans. They help Garn defeat Akkuru, and clear his name with the townspeople, who decide that Garn is ok after all, and go back to being content about having a caveman in their town.