[1] His best-remembered voice roles include Scooby-Doo, Bamm-Bamm Rubble and Hoppy in The Flintstones, Astro in The Jetsons, Muttley in Wacky Races and Dastardly and Muttley in Their Flying Machines, Boo-Boo Bear and Ranger Smith in The Yogi Bear Show, Sebastian the Cat in Josie and the Pussycats; Gears, Ratchet, and Scavenger in The Transformers, Papa Smurf and Azrael in The Smurfs, Hamton J.

[1] He was raised in the Bolton Hill neighborhood of Baltimore,[2] where he received his early training as a performer at the Ramsay Street School of Acting.

[3] Messick moved back to Baltimore a year later, after graduating high school, and approached radio station WCAO about getting his one-man show on the air.

[2] When William Hanna and Joseph Barbera formed their own animation studio, Hanna-Barbera, in 1957, Messick and Butler became a voice-acting team for the company.

On The Flintstones, in addition to many episodic characters and creatures, he voiced Bamm-Bamm Rubble, Hoppy the hopparoo, and Arnold the paper boy.

In narrating The Huckleberry Hound Show and as Ranger Smith in the Yogi Bear segments, he used something close to his natural voice.

He did the voices of the title character in Precious Pupp and Shag Rugg from Hillbilly Bears, both of which were segments from The Atom Ant/Secret Squirrel Show.

In Hong Kong Phooey, he was the voice of Spot the Cat, a faithful sidekick that was the one who foiled the villain's plans, though he let the clueless title character take the glory.

In 1985, new episodes of The Jetsons were produced and Messick returned as Astro, RUDI, Mac, and Uniblab, a pesky robot that worked for Mr. Spacely.

On October 12, 1996, he had a "retirement party" at his favorite Chinese restaurant (Joseph Barbera personally sent a limo to Messick and his wife, and the two were chauffeured).

Many of his friends and peers during his career who had come to pay tribute to him included Henry Corden, Casey Kasem, Lucille Bliss, Maurice LaMarche, Gregg Berger, Neil Ross, June Foray, Sharon Mack, Greg Burson, Walker Edmiston, Marvin Kaplan, Gary Owens, Howard Morris, Teresa Ganzel, Jean Vander Pyl, and Myrtis Martin Butler (Daws' widow).

[7][6][1] Since Messick's death in 1997, Hadley Kay, Scott Innes,[7] Neil Fanning, and Frank Welker have all voiced the role of Scooby-Doo.

In 2000, Billy West also became one of Messick's successors as the new voice of Muttley in the 2000 Dreamcast video game, the 2017 reboot of Wacky Races,[8] and in the Scooby-Doo!