IMHO its a lighting issue. We've all seen deer that appeared almost black in certain light, to have them move to a different area and realize its just a normal deer...
Plenty of big cats around though. I"ve yet to see one other than a drive home once around 1am in highschool when one crossed the road in a flash, but it may well have been simply a big bobcat, I can't say honestly as it was only a short glimpse.
