I honestly found Gabby to be quite interesting, especially given that (as suggested above) she's ideally the most sympathetic among Toy Story movies' main antagonists. Heck, she's even more human than Ernesto de la Cruz from Coco ever was (ironically speaking).
As for the Chameleon, I found her to be okay, though part of this is because I honestly haven't seen Kung Fu Panda 4 yet, but I did see some clips about that movie with her on it via YouTube.