Today is International Talk Like a Pirate Day. This year's pirate honoree is Dynamo Boy, aka Vorm of New Tortuga.
From Who's Who in the LSH #2:
One of the children born to pirate inhabitants of New Tortuga, Vorm enjoyed the exciting, dangerous life there and learned pirate ways quickly. When the pirates' leader asked for a young volunteer to infiltrate the Legion, Vorm stepped forward and killed an opponent to win the "honor". The pirates gave him a hidden belt device with which he simulated special energy-wielding powers in front of Star Boy, who was impressed enough to bring him to the next Legion tryouts. Dynamo Boy passed all tests quickly and gained membership, then proceeded to secretly sabotage all his teammates during ensuing missions and use loopholes in the Legion Constitution to have them expelled. Eventually, Vorm ended up being the only Legionnaire left. Holding tryouts for new members, he screened all applicants to find those whom he might possibly corrupt to his own ends, butg he had no luck until three adults claiming to be Cosmic King, Saturn Queen, and Lightning Lord of the Legion of Super-Villains showed up and offered their serves. The four "Legionnaires" posed as heroes in public, covering their private thievery.
Vorm returned to New Tortuga to report his success and ended up killing the pirate leader in order to establish his supremacy on his own home planet. However, when he returned to Earth, he walked into an LSV trap which sent him off irretrievably into Earth's far future. Once he was gone, the super-villains were defeated by the Legionnaires, who had returned to Earth once they had become aware of Vorm's sinister motives. All expelled members were readmitted. Vorm has not been seen since.
First (and only appearance): ADV 330-331, and he didn't even make the cover of either.
See for yourself: