Big, upright lizard?

Question
This is going to sound crazy - I know, and none of my friends belive me but I have a question. When I was about 5 or 6, living in Upstate New York in the Autumn, I was playing in a pile of leaves when all of a sudden, out of the leaves a large lizard-like animal come out from the leaf pile. It stood and run on it's hind legs, was black and scaley, and had some yellow on it. It was kinda big, maybe a foot tall or more. I didn't know what it was and it scared me, and I went back in the house and told my mom a "little dinosaur was in the leaf pile". We all know better than it being a little dinosaur, but what do you think it might have been? I've tried to do online research and I don't get anywhere. And everyone I ask thinks I am crazy :) Any suggestions?

Answer
To: Rich,

  I just got back from a trip...I read your question and yes there are some monitors that do stand up on their hind legs. But I am going to research these lizards further for you. This is a great question that you have asked me. I'll let you know if I find the answer.

               Sincerely,

                Cece Ericson