I know he loves Peanut butter, but really?!?

My son, my darling boy, announced last night as he, his sister and our "adopted Girl", (Liv's best friend) were making pizza, that he wanted to "change his name". I asked, "What do you want to change it to?" I was trying to not sound surprised, and expecting him to say he wanted to be called "Harry or Gus", but NO, he looks at me with a serious little face and says . . . " Peanut".