In the last e-mail from Glen Gordon he stated the
conexion between Kerberos and Sanskrit Sharvara-, Karbara- "spotted", name
of the Yama's dog. I knew this theory, and it's very
plausible.
An alternative idea:
KERBEROS < IE *K'ERD-GWEROS "heart-eater";
perhaps similar to the Egyptian composite monster Ammut "devourer of
dead".