Dr. E. Bill

Dr. E. Bill is a Doctor who appears at the end of E3 2017 to tell Scott Wozniak that he's been diagnosed with Disappointment.

In E3 2017
When Scott Wozniak finished talking about E3 2017, he was about to give his rating on the show, but then Dr. E. Bill interrupted him to say that he's been diagnosed with Disappointment.

In Night Trap
At the end of the video, when Scott Wozniak was disappointed that his Piss-o-Meter wasn't filled, Dr. E. Bill called Scott Wozniak to tell him that he has a urinary tract infection which brang his Piss-o-Meter up to 100%.

Trivia

 * His name might be a joke on Dr. Evil.