Feuerstein was born in Zell am See, Austria, and studied piano, harpsichord and composition at the Salzburg Mozarteum from 1956 to 1958. He was expelled for insulting the institute's president.[1] In 1960, he followed his girlfriend, a guest student from Hawaii, to New York where they got married.[1][2] There, he worked as a journalist, from 1968 as editor of the German-language newspaper New Yorker Staats-Zeitung,[3] and as correspondent for several German and Austrian media, including the German satire magazine pardon.[1][3] He also worked in the press department of the Austrian consulate.[1]
After divorcing his first wife, Feuerstein returned to Europe in 1969. He worked as a director of the publishing house Bärmeier & Nikel which produced pardon among others.[3] In 1973, he became the editor of the German version of Mad[4] increasing the circulation from 10,000 to 400,000.[5]
Since 1984, he mainly worked in German TV, being partner to Harald Schmidt in comedy shows such as Pssst... [de] (1989–1995) and Schmidteinander [de] (1990–1994).[3] In 1994, he received the Bambi television award for creativity, for "anarchistische Originalität" (anarchic originality) and "hemmungslosen Mut zum Chaos" (uninhibited courage for chaos).[1] He then left the show.[1]
In 1995, he starred in the TV film Entführung aus der Lindenstraße. Twice, in 1997 and 1998, he hosted twelve-hour-long live TV shows, dubbed Feuersteins Nacht (Feuerstein's Night), for WDR.[6] He also worked as the dub voice of Gilbert Huph – to whom he bore a striking optical resemblance – in the German-language version of Pixar's The Incredibles.[7] He appeared on stage, especially as Frosch in Die Fledermaus by Johann Strauss, 75 times at the Cologne Opera between 2004 and 2008.[1]
A native Austrian, he became a German citizen in 1990.[7] Feuerstein died in Erftstadt aged 83.[1][3]