Dr. Henri LaPlante is a physicist in the Imperial Science Bureau who defected to the Rebel Alliance. He specializes in reactors and scaling power sources. After he was bitten by a Pantano eel tainted with the Dark Side of the Force and wandered off from Delta Base, he was recovered by "The Called" and joined the crew of the Cantina Turner on a pilgrimage to the South Pole. He survived the Imperial assault there, and soon rejoined the Rebellion to begin work on the ship the Taunagi.
Behind the scenes
"Henri LaPlante" is a poor attempt to just straight-up name a character "Enrico Fermi" by making it French-ish (New Orleans, 'member?). Planté means something like "robust" but also "well-positioned," because of some reference to putting down roots(?), and I added the article and dropped the diacritic just to feel cajun, even if the result is a dude named "Henry the Plant" instead of "Henry from Fermi".