Adventure 372 (Sept 68) sees Timber Wolf’s long-awaited entry into the Legion, as well as Legion Academy member Chemical King, but Jim Shooter and Curt Swan also provide the earliest chronological appearance of the Legion of Super-Villains in this tale.
After being expelled last issue, Colossal Boy gets recruited by Tarik the Mute for his new Legion of Super-Villains. He joins expelled member Nemesis Kid, as well as Legion rejects Radiation Roy, Ron Karr and Spider Girl.
Meanwhile, Bouncing Boy gets around to showing Ultra Boy the “life gem” he discovered at Gim’s place. Shame he didn’t bother to do that when he showed him the missing training manuals. Realizing the actual situation, Ultra Boy has Superboy, Chameleon Boy, and Academy members Timber Wolf and Chemical King adopt disguises to infiltrate the LSV.
As well as the villains mentioned before, they also discover Lightning Lad’s missing brother Mekt, in his earliest story.
Colossal Boy figures out who the Legionnaires are, and exposes them, rather than risk his parents’ lives. Neither Timber Wolf nor Chemical King show particular prowess in their first outing.
Chameleon Boy pulls off a really impressive transformation, impersonating Superboy, and then pretending to turn to glass, and then into shards of broken glass. That last change really should be beyond the range of his powers, being dozens of separate objects, but there would be a couple of stories in which he adopted multiple forms like that.
The Legion raid the LSV, and Colossal Boy is restores to Legion membership, while Timber Wolf and Chemical King, neither of whom did anything particular in this story, become members as well.
This story is also the final Curt Swan Legion tale in Adventure.