I thought the crest was just another instance in the series-long joke. Nobody is supposed to know Monroe's surname and they used Blutbaden as the name on the crest to further the joke. That's like someone's name being Homosapien on a crest for humans. It would be obvious that it was a joke from the writers who don't want you to know the last name.
In a related note, I remember That 70s show never revealed Fez's last name or what country he was from. I'm more certain of the latter than the former. Fez would always get interrupted or he wouldn't really answer the question and made a snappy retort.
Also, I recently watched the Hey Arnold movie that was released last year and they finally revealed his last name. It was ironic because his grandfather called him by his last name all along but it was just thought to be a nickname.
In a related note, I remember That 70s show never revealed Fez's last name or what country he was from. I'm more certain of the latter than the former. Fez would always get interrupted or he wouldn't really answer the question and made a snappy retort.
Also, I recently watched the Hey Arnold movie that was released last year and they finally revealed his last name. It was ironic because his grandfather called him by his last name all along but it was just thought to be a nickname.