My vote it for the zig zag eel! It is a member of the spiney eel family but it stays even smaller then the peacock eel. It will only get to be about 7inches long. I love mine! I am looking to get another eel as well, either another zig zag or a peacock because they stay small. I don't think the school would be very happy with me if I had to house a 3ft long eel like a tire track or a fire eel!!