Although the format of the show and the cast -LRB- and ages -RRB- of characters have varied significantly over the years , the most familiar versions of the show feature a talking dog named PERSON@1 and four teenagers or young adults : PERSON@2 , PERSON@3 , PERSON@4 , and PERSON@5 `` Shaggy '' PERSON@6 .

Though the show , people in it , and their ages have changed , the most familiar versions of the show have a talking dog named Scooby-Doo and four teenagers : PERSON@7 `` Freddie '' PERSON@8 , PERSON@3 , PERSON@4 , and PERSON@5 `` Shaggy '' PERSON@6 .
