The community grew out of the elven online community of the early-to-mid-1990s, with the earliest recorded use of the term otherkin appearing in early 1996; however, from the context it appears in, the term seems to have been well established in certain communities by this point already. According to otherkin.net, the term was originally coined when it became clear that a new subculture of people identifying themselves as a number of different mythological creatures, such as fairies, unicorns, and satyrs, and not just as elves, was emerging.

However, the term has expanded in its meaning over time and is often used nowadays as a term to describe a number of distinct but related communities. Examples include the draconic, vampiric and therianthropic communities, all of which share similar core beliefs but, according to otherkin.net have members who do not consider themselves part of the overall otherkin community. Although some furry lifestylers (a subset of the furry fandom) also hold beliefs similar to those of the otherkin community, there is debate in the two communities over whether or not to consider them "otherkin" as well.

There is some overlap between many role-playing and otherkin communities, and some otherkin beliefs are similar to elements found in role-playing games and other fictional sources. Others at otherkin.net, however, stresses the difference they see between pretending to be a non-human and actually believing oneself to be non-human.