About 9 months ago I bought 6 small (2 cm long) goldfish (poisson rouge) from the local Bricomarche. They came home together in a single small plastic bag along with a tub of fish food. I thought that it'd add some life to our pond and help keep the algae at bay a bit.
Now we think we have somewhere between 60 and 100 fish ranging in size from more than 15 cm to less than 1 cm. We have 6 very big fish which we think are the original beasts.
It's difficult to get a good picture of them all but this gives an impression.