Try and wrangle your way into the restaurant in the reptile house, there were mudpuppy and Chinese giant salamander on display there which otherwise weren't viewable.
Unfortunately when I visited on week days in mid-September, that restaurant was closed. During a week it might be open, but I think only if the weather is good enough and there will be enough people in the park.
Damn, I wish I'd realised that - it's been well over a decade since I last saw mudpuppy!
I don't know how recent you visited, but the Thai restaurant with terrariums in the Mersus Emergo reptile house ship only opened in early 2022. Until 2021 there was only a small restaurant without terrariums in the Mersus Emergo.