of the common stuff, species like chainlinks, banded, and freshwater morays would work out in terms of temperament, diet, etc....I've kept G. tile with snowflakes on a couple of occasions and have never had aggression other than the usual during feeding when eels go nuts...I've kept a snowflake with banded for a brief time and never had issues either. I imagine the same can be said with most of the common Echidna morays