I had one years ago,...it was amazing to watch it ever so slowly " dog paddle" across the tank in order to catch a feeder goldfish.....it would take him a couple of minutes to manuver himself in position, kinda like watching a floating log just barely moving but once it got near the goldfish and attacked, it was just a blur and the only thing you saw were gold scales falling,.....probably one of my favorite fish I've ever had in a tank.