Just throwing this out there, but you should never feed goldfish to snakes. They contain a chemical called Thiaminase that affects how snakes can break down vitamin B. It's usually not a problem if you don't do it all the time, but some snakes can be more sensitive than others and have serious neurological symptoms or even death after only a time or two.
This is a really common problem with garter snakes, as they are more commonly fed fish, but the Thiaminase problem can potentially affect any snake species.