Benny's hair

Though her character notes or subsequent biographies don't hint at her interest in follicular fashion, Bernice Surprise Summerfield has probably had more haircuts than all of the Doctor's other companions put together. I'm in the middle of my fourth recent reading of a New Adventure, and her hair has been different from her default look:

• in Human Nature she has hair extensions
• in Set Piece she has grown her hair long and dyed it blonde
• in Lucifer Rising she put it in dreadlocks
• and in Sky Pirates! she has it cropped.
  

I'm sure I remember other novels with different do's, too. It's appropriate, given her status as first novelistic companion. Changing hair is uniquely possible in novels. In comics, looks must be iconic; in television, it's subject to actor cooperation and continuity; in radio, no one has hair.