Sometime in the early 80's, radio and cartoon legend Casey Kasem joined Jerry Lewis' staff of co-hosts for the annual Muscular Dystrophy telethon. In this clip, approximately from 1987, Casey decides to reach out to the young cartoon fans. CaptainOT uploaded this clip to YouTube:
Zoinks! The only other time that I can think of that Casey did his Shaggy voice on camera was when he acted as a fill-in announcer on Ricki Lake's talk show a few years back. Casey has scaled back on his voice work in recent years, as he currently voices Shaggy's father on Scooby-Doo: Mystery Incorporated for Cartoon Network, while actor Matthew Lilliard, who brought Shaggy to life in two "Scooby-Doo" feature films, takes over the iconic role full-time (and doing a good job of it, too). It's too bad I missed this the first time around. That would've woken me up for sure!