My fiance is
Caspar. When he was younger, he got teased a bit about being a "friendly ghost", but he really loves his name now. People constantly misspell it as
Casper, even his family. It is often misspelled on important documents that he then has to have reprinted. Although there are some downsides, he has never had to deal with the
Cass nickname. Since it's a 2-syllable name, it has always been short enough to avoid that.