What is the plural of ‘Pegasus?’

Mark A. Mandel, linguist (i.e., language scientist and researcher), PhD in linguistics

The original was Greek, but we adopted it in English in the Latin form, ending in -us, not the Greek -os. So we use “pegasi”, not “*pegasoi”. We can and do also use “pegasuses”, as we say “campuses” and “calluses”: Eunji Choi is right about expressions like “the Mickey Mouses of the world”, but that’s not relevant here: “pegasus”, like “atlas” and “medusa”, is proper only in origin.

Pegasi
Downtown Dallas
Texas