Invalid unicode characters in username (message index from Data Package)

I just downloaded my Data Package, and I noticed that some of the usernames of the people I've DMed have unicode characters in their names (obviously, you can't have special characters and stuff when all you have is plain text in a JSON file). However, one of them has invalid characters. Can someone show me what they are so that I can copy and paste them into my quick switcher to see who it is (out of curiosity)? The characters are as follows: \ud835\udd4d\ud835\udd5a\ud835\udd65\ud835\udd65\ud835\udd60\ud835\udd63\ud835\udd5a\ud835\udd52\