It did startle me for just a second then I realized it looked familiar and was being very still. Last year when we were fighting the nesting birds in the eaves of an open shed we placed rubber snakes there to scare them away. It must have fallen then I raked it up without noticing and dumped it in the brush pile the day before!
There is one under the lid of the gas tank right now, I just hope we remember to move it before the tank needs filling up again or someone else may be startled!!