However, the term is often used to refer to the Eastern Grey Kangaroo (Macropus giganteus), which is the most abundant and widespread kangaroo species in eastern Australia.
It's important to note that the Red Kangaroo (Macropus rufus) is the largest kangaroo species and is also extremely common in Australia. Both the eastern grey and red kangaroos are considered "common" due to their vast populations and widespread distribution.
So, while there isn't a specific species labeled "common kangaroo", it usually refers to the Eastern Grey Kangaroo or encompasses both the Eastern Grey and the Red Kangaroo.