I have held my thoughts in about this topic for some time. For fear of public ridicule. But I say, the heck with it, let's have fun.
I thought the Ergon was scary when I first saw it.
Yup, there. I said it. Go ahead and mock me for being freaked out by the chicken-headed creature. But it's true.
I was a kid when I first saw Arc of Infinity, and when I saw this semi-skeletal beast coming out of this fog-filled doorway, that was creepy.
And since we're on the topic, I felt really bad for Omega in that episode. He was just trying to get his life back, and he was decaying so rapidly. Remember the part where he's watching the puppet show standing next to the kid? How sad was that. He just wanted to live a happy normal life.
And then the Doctor blasted him with his own gun. It seemed merciless. I couldn't understand why the Doctor didn't try to help him instead of blasting him with the gun. It was so cruel. In past episodes, the Doctor did more debating whether to destroy the Daleks than he did over the life of Omega. It was like a no-brainer for the Doctor. Just blast him and end his attempt at a happy life.