That satan went back in time to place the fossil record in all the newly forming rocks so that they would mess up the radio carbon dating to make people think that the earth was older than it really was.
Flaw in the arguement being that if a creative day was 7000 years, satan would have had to repeat this process several thousand times to have made up for the billions of years difference.
Even as a brainwashed 11 year old with an unhealthy interest in science I found this one difficult to swallow.
Then there was the story during the 'spiritualism' paranoia of the 70's.
A sister in an undisclosed location bought a coat from a second hand shop. For weeks afterwards she would hear satanic voices at night. In the end the elders were called in and identified the coat as the offending source of the demonic possession. They took the item into the garden to burn it. When the coat crawled out of the fire screeming.
I was only 7 at the time I heard this and had nightmares for months.