Jimmy Neutron: Cindy Vortex

Cindy is Jimmy's simultaneous rival and romantic interest. She is a mixture of a semi-protagonist and antagonist.

Cindy, as said, is a bit of an antagonist in a way, even though she's very smart and competes with Jimmy and she gets jealous of his superior intellect sometimes. She is very prideful, tomboyishly beautiful, stubborn, kind, and persistent, and she was shown with these personality traits throughout the series.