Kash Biermann
Reality star Kim Zolciak and Atlanta football player Kroy Biermann have several kids together, all of which have "K" names. The standout is one of their older sons, Kash. There is also Kaya, KJ, and Kane.
Lourdes
Madonna's daughter Lourdes seems to go by one name, just like the singer, Lorde. No relation, though. She's currently a student at the University of Michigan. Aside from school, she's an actress and model who works for Stella McCartney.