great!!! my snowflake eel was always awsome to my clown fish! then he ate him.... JUST KIDDING!! the clownfish went to another tank where the snowflake will soon be upgraded too. It depends entirely on the eel though. the only time my gets the slightest bit agressive to anything is during feeding time and my valentini puffer (named rulf) tries to steal his krill. Besides that mine is very very well behaved. This does depend on the eel though. you should definatly get the eel when he is tiney though. my eel will only eat krill, wont eat silversides even. so i am safe as far as fish go. but many have been known to eat anything that fits in their mouth.