Black object was moving slowly across the sky and did not look or move like anything I had seen in the sky before

While watching the "Birds of Flight" show at Disney World on August 26, 2015, I noticed a black object hovering in the sky.  The object was moving slowly across the sky and did not look or move like anything I had seen in the sky before.  It was taller than it was wide and did not display any distinct symbols.
After watching it for about 30 seconds to a minute I was unable to indentify what it was but am certain it was not a plane.  It appeared to be either below the clouds or at cloud level because at one point a cloud passed behind it.
Based on it movement it was maybe moving as fast as a hot air balloon does in the sky. It's speed or direction did not change while I was watching and I lost interest. I did look up a couple times after my initial siting to confirm what I had saw and the object was still there.  I did not however see what happened to the object.