Barney!

Given: Barney is a CUTE PURPLE DINOSAUR
Prove: Barney is satanic

The Romans had no letter 'U', and used 'V' instead for
printing, meaning the Roman representation would for
Barney would be: CVTE PVRPLE DINOSAVR

CVTE PVRPLE DINOSAVR

Extracting the Roman numerals, we have:
CV V L DI V

And their decimal equivalents are:
100 5 5 50 500 1 5

Adding those numbers produces: 666.

666 is the Number of the Beast.

Proved: BARNEY IS SATANIC!

OH EM EFF GEE! o.O