It's too bad they never roasted Scooby-Doo. Then again, there's still time for that.
Anyway, Frank Welker made a rare appearance in front of the camera when he was invited to appear on the Dean Martin Celebrity Roast when they honored George Burns in 1978. Frank shows up around the 45 minute mark to do a mimic of Walter Cronkite, referencing Burns' hit movie, "Oh God!".
You'd think they'd have done a roast of Scooby by now, but no one at Hanna-Barbera or WB or their various network partners ever gave it much thought. Hmmmmm. It would make a pretty good DTV down the line, don't you think?