Being a T-Bucket owner, I take a second look at other T's I run across. I've seen a couple that were absolutely loaded with skulls, other bones, creepy & grisly stuff - even one that was towing a coffin behind it. How about a differential cover that is stamped to look like a skull? Yup.
I seem to remember that Herman Munster drove a T in the comedy series 'The Munsters'. The skull theme would fit well with that series. Was that where it started or was it earlier than that?