Shtarker is Siegfried's chief henchman in the Get Smart series. Shtarker is an overzealous lackey whose most notable trait is his abrupt personality change from sadistic villain to presumptuous child, interrupting conversations to helpfully elaborate, using silly vocal noises to imitate things such as engines or guns. This prompts Siegfried to utter his catch phrase, "Shtarker...Nein! Zis is KAOS! Ve don't [weakly imitates Shtarker's sound effect] here!"
(In the DVD commentary for the first episode in which the character appears, in season two, Bernie Kopell notes that "shtark" is a real Yiddish word meaning a person of great strength.)
He was portrayed by King Moody in the series, and by Ken Davitian in the 2008 film. He appeared as the quaternary antagonist in the film, although he wasn't as active.