Barney, the cute purple dinosaur, is Satan.
Given: Barney is a cute purple dinosaur.
Extract the Roman numerals:
(and remember that the Romans had no letter 'U',
they used 'V' instead)
CVTE PVRPLE DINOSAVR
CV V L DI V
100 + 5 + 5 + 50 + 500 + 1 + 5 = 666
Q. E. D. We suspected it all along.