Martin van Waardenberg plays Buurman Baasje on Sesamstraat, the Dutch co-production of Sesame Street.

Buurman Baasje (Next Door Neighbor Bossy) is the grumpy neighbor who lives around the corner, behind a big fence. He hates it when Tommie, Ieniemienie, Purk and/or Pino disturb him, but with the help of the other actors, he is usually a victim of his own grumpiness.

Buurman Baasje's real name is Mr. Drommel; when the new neighbor called Tommie "baasje" in his debut episode, Tommie invented his nickname.

Buurman Baasje was added to the cast when Aart Staartjes, who originally played the grumpy character on the show, announced that he would be retiring from all children's TV except Sesamstraat. Since the new neighbor's arrival, Aart has become a little tamer.

Van Waardenberg is a comedy actor and performs as part of the duo Waardenberg & De Jong.

He was the first member of the human Sesamstraat cast in years whose character does not use his own first name. Mieke Verstraete didn't, and although Gerda Havertong used to be called Gerda on the show, she usually plays Aunt Peetje nowadays. She hardly ever plays Gerda anymore.