Enbyphobia (also called exorsexism) is the irrational fear or hatred of those who do not identify as either male or female, but as a gender outside of the gender binary.
Those who display enbyphobia can be either cisgender or transgender, and are usually binary, however, non binary and genderqueer people can experience enbyphobia, an example in the case of someone who is agender and insists that only bigender and agender are valid gender identities for non binary people. These people would be accurately described as enbyphobic, even if they support or understand some non binary genders.
Enbyphobia is similar to transphobia and considered a form or variant of it.