Yes, in my post I said peacock eel, which stay small. Though I would definitely not put an 18" eel in a 60 gallon. The problem is more in the severum, an adult severum would need this tank size to itself in my opinion. I'd say you should re-home the severum or rehome everything else. Maybe the blood parrot and cat could live in there with it, but maintenance would get tough eventually.I think my eel is a smaller type of eel I posted a photo of it a one person said it was a type of eel don't remember name I googled the name and it said it only gets to 18 inches max if i replace knife do you think my tank is still over stocked