He is the German voice of Neil Patrick Harris, Ewan McGregor and Owen Wilson.

In 1983, having been discovered by George Roy Hill, he starred in the movie The Little Drummer Girl along with Diane Keaton and Klaus Kinski.

In 1987 he was a member of Joanne Woodwards group Actor's und Director's Lab.

Moog is the recurring voice actor of Orlando Bloom, Owen Wilson and Guy Pearce, too.

Since How I Met Your Mother he voices Neil Patrick Harris in his movies and TV appearances.