I'm intrigued now. What name could be so
mortifying ?

(apart from Jimmy's jingle jangles - that's plain offensive and I'm surprised the KC didn't disallow it!)
I know that one person's nice is another one's nasty. But
mortifying?
I think it would be good to fess up here and see if we agree ;-)
I do think you are right to want to change it though, if you feel that badly about it.
One of the things I took a lot of trouble with, and wanted the new owners to feel happy with, was our pup's names. I wanted them to feel proud of their new babies and this is part of it :-)