Appropriate tank mates for this eel would be triggers, large angels, and other large semi aggressive to aggressive fish. These eels have teeth to grab and rip, it's not about fitting in it's mouth. If they are small right now, their temperament may be mild, but as they mature, within a year or so, they'll be a force. An appropriate eel mate for your tank would be something like a skeletor or banded. A snowflake, like the other 2 I mentioned, are pebbletooth eels, These eels have blunt teeth and as long as appropriately sized, will pose no danger to fish.