Originally, all hairy gay men were seen this way, until the term was appropriated by larger people, with different terms being coined for those who are hairy but with a smaller frame. The background of the term is necessarily intertwined with that of the term bear, which became popular in 1970s San Francisco. There are otters of all ages, with younger ones often being called cubs. Other differences between these two categories are that otters are generally more accepting of more feminine appearance, behaviour and body types, such as twinks.
As such, the term is used to describe the stereotype of bears' smaller, more lean, and potentially more effeminate counterparts. Otters, the comparison goes, look a bit like small bears. The term is a subset of the term bear, which describes the stereotype of hairy and big gay men.
