Drummer Smurf (original French name Schtroumpf Tambour) is a character who appears in the Smurfs comic books. He uses his drum to call the attention of the Smurfs and then give messages to the whole Village.
Confusion with Harmony Smurf
The first time a Drummer Smurf appeared, it was in "King Smurf", but he was Harmony Smurf, who got from King Smurf the job to give messages like the order of making a palace, or the upcoming search for the rebels' camp. The other story where the Drummer Smurf is clearly referred as Harmony Smurf is "A Smurfy Party" from "The Baby Smurf".
Other appearances of the Drummer Smurf were assumed to be still Harmony Smurf, until "The Finance Smurf" showed Drummer Smurf reading a message given to him by Harmony Smurf. In "The Reporter Smurf" he becomes the distributor of the Smurf Village newspaper. In The Olympic Smurfs, he announces that Hefty has organized games with a medal as a prize, but none of the Smurfs care. so hefty whispers something to him and Drummer adds that the winner also receives a kiss from Smurfette.
However, most times a drummer appears, it's unclear if he's Harmony Smurf or Drummer Smurf.
Harmony reprises his role as a drummer in the animated version of "King Smurf", and in other episodes, he's the one calling the Smurfs' attention to give messages, using his trumpet rather than a drum.