Just because there's a lot of pre-Roman cthonic dieties - yes, I know this starts with Greek, but bear with me a moment - like Hekate as an example, I'd be strongly inclined towards any 'earth' based definitions. Gods who preceded the current ruling culture were obviously made canonical parents or other predecessors, or passed into an afterlife guardianship.
No, Internet, Kerberos is Probably Not “Spot” – SENT...