The frog's main adaptations are less of a dependency on water, brighter colors, stronger/bigger legs, and a sleeker body. A frog would need to be able to survive with little/less water since the land may dry up, so I would say that their skin could potentially use mist or dew in the morning, to hydrate, since they don't drink water, they absorb it in swamps. Less water and food means more predators, so the frog's sleeker body, with stronger legs, could help it move faster and further. Additionally, it could develop brighter colors to mimick its poisonous kin. I know the frog looks spooked but he's been through a lot.
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