The Kois are all really pretty! I wish I could get one but my 5 gallon tank isn't really for that. Your Leo, is a plecostmus, We use to have one named monster, if you don't keep them in a tank big enough for them or if they get tired of their diet, sometimes they become aggressive and can kil the other fishes. Also know to suck the slim and scales off of anglefishes and Kois when they sleep. They are nocturnal too and prefer to hide in logs. Just a warning, though they are very docile when they are well feed. Wish you good luck