Cubone Theory - I have always felt like this was true. Now I really thing it is. Cubone is a baby Kangaskhan . Like this post says, Cubones wear the skull of their dead mother. I feel if this theory is true, no one will be surprised.
This is exactly what happened to me. I was scared to battle it because I didn't have any poke balls but then it said that it just joined my team and I screamed. And while This happened my dads friends were over so it just became weird