An eponymous marsupial is a marsupial that's named after someone or something. There are many synonyms for "eponymous", such as "namesake" which also means "something or someone that's named after someone or something." Another synonym for eponymous is "homonymous", which means "having the same name as another thing or person." Other relevant synonyms include "self-named" which means "named after oneself," and "autologous" which means "pertaining to something originating from the same organism it belongs to." Ultimately, the choice of synonym depends on the specific context in which the word is being used, and the desired effect the writer or speaker wants to achieve.