It’s the brown thing in the middle. 
Copperheads do seem to be incredibly docile. I’ve encountered both them and rattlers numerous times in my life and the copperheads seemed extremely eager to get away quickly while the rattlers stood their ground. When I was a kid I was running down the steps to our old-school potato cellar (basically an underground brick bunker) and I must have startled one. It slithered right past my foot for two or three steps in the same direction before I did an about face and gtfo.
