Aviva Corcovado

Aviva always wears a yellow jacket with blue stripes down the arms over a gray shirt and blue jeans. In the first-completed episode "Polar Bears Don't Dance", her ears were pierced, she had prominent streaks in hair, and she skated everywhere using Wheelies-type tennis shoes, but lost these traits in subsequent episodes (although the Wheelies stayed for a few later ones). She keeps her hair back in a ponytail. She uses Spanish exclamations, but did so less and less throughout the show that to the point that in some episodes, her lines are entirely in English.

Aviva is the leader of the Tortuga gang, second in command to Chris and Martin. She designs all of the inventions the Kratts use, usually nature inspired. She is an engineer and inventor. Once she has made up her mind, it takes appealing to her emotions and overwhelming evidence to change it. She is also competitive, rivaling Zach in invention contests, the Kratts, and even nature itself (most notably in "Cheetah Racer" where she bet that she could invent a land vehicle that was faster than a cheetah). Although she was proved wrong.