Also known as Battalia in the English dub.
Penne first shows up in episode 5 and joins Team Freedom after the events of that episode. She's responsible for both renaming the team "Freedom" and designing the logo—a solid upgrade from whatever Arashi had tried to come up with the episode before.
Her backstory is pretty rough. Her parents were killed by bandits when she was a kid, forcing her and her Scorpear into an orphanage. Being able to ride Zoids gave her an edge, so she became a bounty hunter and got pretty damn good at it—successful enough to eventually track down and capture the very bandits who'd killed her parents.
When word spread about the Death Metal Empire hunting for the Wild Liger, Penne saw an opportunity. She approached Arashi with the intention of earning his trust, planning all along to betray him for the bounty. She almost pulls it off, but at the last second she abandons the plan and instead turns on Foiegras, one of Death Metal's Four Heavenly Kings.
It's only after defecting from Death Metal that her Scorpear finally grants her its Zoid Key.
Content compiled by AnimeList.moe from publicly available sources.