That was a lot more fun than I expected it to be.
"*gasp* He said the line!"
Also fun fact: Fred was voiced by Frank Welker, the original Fred from the very first series, "Scooby-Doo, Where Are You?" in 1969-71. He also voiced Scooby in this episode as he does now for a lot of Scooby-Doo productions, though he wasn't the original Scooby when the franchise started. He's also familiar if you've basically seen any cartoon ever made between the 1970s and now because he's in pretty much everything (as his 800+ IMDB credits will attest)