This is the Asiatic Painted Frog, also know as: the banded bullfrog; (Kaloula pulchra pulchra); the chubby frog (in the pet trade); Asian painted frog; rice frog; or bubble frog.
Here it is at night, using a bounce off body flash and a flashlight.
These frogs, belonging to the microhylid (narrow-mouthed frog) family, and they have big fat round bodies....which they can swell up even more when alarmed/attacked by predators. They are best known for their very loud "mmmmmmmooooooooooorrrrrnnnnnnggggghhhhhh" call at night, and can be found both in and out of water, as they are typical burrowers and often live in holes - and can be seen in drainage holes. They can exude a thick, very sticky fluid which makes them unpalatable to most predators, and its main enemy is the Chinese Cobra.
This one is under the water showing its distinctive patterning.
Males have darker throats than females. These frogs grow up to 10cm or so, with females generally being larger than males, and they may live for as long as 10 years. They are well established in the pet trade as a common pet - the chubby frog, as they are easy to look after, and eat voraciously.
In Hong Kong they can be seen next to ant trails, occasionally gobbling one up.
They are not very good swimmers.....here is one trying his best......