Human refers to a real-world species, a fictionalized version of which appears in various media.
Absence from various media
Though humans are commonly present in the Prime Universe, there are instances in which they do not appear. Indeed, in some cases the presence of humans is an abnormality. In the Darkwing Duck episode "Twitching Channels", for instance, Darkwing Duck encounters humans in an alternate dimension and is horrified by the sight of the "beakless mutants!" Humans are similarly absent from DuckTales 2017, with the exception of an altered reality seen in "Quack Pack!", in which they are similarly regarded with revulsion.
Typically, humans have some common characteristics: they are usually bipedal and with two arms, which are shorter than their legs. However, humans can vary greatly in other aspects of their appearance, such as skin tone, hair and eye color, height, and so on.