Nepeta

Nepeta is...

the camp's resident tinkerer and builder, and is known for cobbling together all sorts of crazy devices. Despite her occasional hijinks, she has a heart of gold.

Biography
Nepeta didn't really come into her own until Season 2; previously, she'd mostly been the "techie" background character. While there was emphasis on the mischief she, Eve, and Fliss got up to, she also saved the day on several occasions, and was generally depicted as an extremely kind and caring friend.

Like Tessa, she's known for being the source of small explosions from time to time, though she will always avow that they weren't supposed to happen.

Behind the scenes
From the start of Season 2, Nepeta quickly became a fan favorite, prompting the writers to develop her character further beyond just "gadget girl."