The come in different colors
You will want to collect them all 
Ok la you can feed it chicken fillet if you want to but most ppl
like to give them live food to see them hunt
PS. That vid ain't gross. You should see the youtube where this
guy fed his fishes live mice. You can see the blood and the gore
-_-"
I think if I kept one, I'll feed chicken and beef, sliced up and
cooked. 
The only fresh thing it might have, would be
houseflies, because I hate the houseflies here!
The way you said, "collect them all" makes them sound like some
limited edition toy!
