Agent 7

Agent #7 works for Dr. Phineus Phibes.

Season two
Agent 7 & 8 were used a nano-tech guinea pigs and temporarily transformed into a frog and fly, respectively, with predictable results.

As a temporary side-effect, he still ate flies with a prehensile tongue even in human form. (Agent 8 had also somehow been spared.) (Shaggy And Scooby World)

Appearances

 * Shaggy & Scooby-Doo Get A Clue!
 * Shaggy And Scooby World