Check this Barney the dinosaur theory out.

 1) Start with the given:
         CUTE PURPLE DINOSAUR

 2) Change all U's to V's (which is proper Latin anyway):
         CVTE PVRPLE DINOSAVR

 3) Extract all Roman Numerals:
         C  V  V  L  D  I  V

 4) Convert into Arabic values:
         100  5  5  50  500  1  5

 5) Add all the numbers:
         666

 Thus, Barney is Satan.