Jakob is an Israeli tour guide in charge of the Simpson family's tour to Israel. His niece, Dorit, is extremely effective in the Israeli martial art of krav maga, from which Bart Simpson suffers great physical harm.
Jakob is known for his stereotypically Israeli demeanor, most commonly saying, "Yalla, b'seder, you can shut up now!" and doing a lot of talking with his hands. He also repeatedly says "Shut your face" to the tour group, evidently either ignorant or uncaring that many English speakers are likely to find it offensive.
