i have one left, had about 20 of them in the past, they're real cool, looks nearly identical to the sabertooth characins, or vampire tetra, however, they're not a characin at all. they don't have any fangs, but just small fine teeth for grasping food. they are predatory, swim and act just like any of the hydrolycus sp. the largest i've seen them was at about 15" but purportedly they grow larger, they're pretty hardy. almost never seen in the hobby. pretty peaceful towards anything too large to be eaten.