Attached Link: http://homepage2.nifty.com/%7Emr_trout/models/poserModel.html#Figure

The only cartoon fish that I know of is the one at DAZ. It is a goldfish, but with a color change and a diet could pass as a guppy (toonimals aren't realistic, so just being a fish might be enough for your purposes). I don't like this fish because of the flatface, but others do... a matter of taste. Trout's fish are among the best. Most of his props are .3ds format and I don't know if he's done a guppy. Some of his stuff is at this link, but he has pages of fish and flowers elsewere, too. Carolly