This is Musk's youngest son, Lil X. Yes, there is an X in his name. Musk has a particular fondness for the letter X.
Not only did he rename the acquired Twitter to X, but he also named his aerospace company X, and even included an X in his son's name.
Musk believes that X represents the unknown, embodying infinite mysteries and exploration. It indirectly reflects Musk's yearning for science and his endless pursuit of truth.