As we all know, Bert is a beloved character of our childhood. Upon closer examination, we find that he has far more sinister motives in mind.
Let us examine Bert's love of pigeons! Could it be that Bert is overly fond of his fine feathered friends? For Bert's beloved "Doing the Pigeon" dance reveals his true sick motives!
Bert is left handed, a well-known indicator of evil.
Bert's favorite number is 6. As in 666!
In addition, when one reverses Bert's name and triangulates it in a quantum mechanical equation as blessed by seven aeons of pain....you get Lucifer! Clearly, my friends...BERT IS SATAN!