This poor creature is a Chinese edible bullfrog. Clearly part of a recent buddhist (mercy) release, as there were around 6 of them sitting like this in a pond in Lions Nature Education Centre.
No wild animal would willingly expose itself so obviously.... this poor creature will have an unhappy life, probably chomped slowly to death by another invasive animal, the red eared slider, that are thriving in this pond. This frog meanwhile competes with local wildlife for food, and can also spread terrible and devastating diseases into other local animals. This horrible practise sustains a thriving industry for those who trap, trade, and sell animals for release – mostly birds, fish, and turtles. Calls for regulation go unheeded.