Reports of the Australian creature called the Bunyip come from Aboriginal folklore and from modern sightings, centered especially on Lake George and Lake Bathurst. In traditional folklore, the Bunyip is a very aggressive animal with supernatural characteristics, but in modern sightings, the Bunyip is generally harmless and seems less supernatural. Beyond the fact that it is hairy and aquatic, the descriptions of exactly what the Bunyip looks like vary from one witness to the next.
Generally, the Bunyip is thought capable of coming out of the water, though it seldom goes very far from a lake, river or stream. The idea that you could meet this creature in the bush means that the Bunyip is more than just another lake monster. Sometimes the Bunyip is really huge, other times merely the size of a big dog. Sometimes it resembles some undiscovered variety of freshwater seal, and other times it sounds more like a traditional lake monster, with a long body and horse-shaped head. Drawings of the bunyip generally do not agree with other drawings of the Bunyip.
If the Bunyip exists at all, it sounds like more than one cryptid could be lumped under the same label, a sure recipe for disaster when science looks at any problem. Perhaps some Bunyip sightings represent lost seals or swimming dogs under bad lighting conditions, while other sightings may represent a true cryptid that could be another lake monster of the usual type, a giant otter, or perhaps an undiscovered aquatic marsupial. Without better categorization of the data, it is really hard to make much sense of any truth that might be hidden in it.
If we look past the many problems, we can perhaps envision a dog-like hairy water monster that seems related to the doyarchu and other seal-like or otter-like lake monsters found in legends from around the world.