Yes, this is about the cryptid.

I'm trying to translate "mothman" (or "moth gods") into Irish, and the internet is telling me it's "leamhan," which in English means "moth." That's,,, not exactly what I'm going for. I'm also getting that it translates back into English as "elm," but isn't that "leamhán" with a fada? (So now I'm skeptical of the online dictionary I had been using).

I have no idea how to say "moth gods" in Irish.

I was having a conversation with my friend about these, hence the weird words I'm trying to translate.

moth = leamhan,
genitive leamhain is used if attribute of another noun.

man = fear
mothman = fear leamhain
men = fir
mothmen = fir leamhain
men of the moths = fir na leamhan

god = dia
moth god = dia leamhain
gods = déithe
moth gods = déithe leamhain
gods of the moths = déithe na leamhan

And, yes:
elm = leamhán

bluberrysunset, are you from West Virginia, USA?