The fun uncle in the family is usually a pushover, someone the kids count on to join in their games rather than put a stop to tomfoolery.

When Jackie Coogan was charged with bringing Uncle Fester to life for The Addams Family, he loved stepping into his "fun uncle" shoes. His only wish was that he was allowed to get involved in even darker high jinx on the show.

"For me, as an Addams fan, I'd love to see the series more macabre," Coogan told the Democrat and Chronicle in 1965.

If you've seen any of the "Uncle Fester" character in comics (he was not named originally), then you understand what Coogan means.

In one of Addams' single-panel cartoons, Fester sits cheerfully reading about toxicology in a room decorated with the heads of lovable animals like a puppy, cat, and bunny on the wall. In another, Fester surveys "cold dishes," like shrimp salad or mincemeat pie, staring enticingly at a man's head served on a platter.

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Coogan wished he could take the "ookiness" of the character just as far on TV, and even suggested doing a late-night version of the sitcom so that audience could see the real Addams Family.

"I'd like to do the real Addams, say at two in the morning," Coogan said. "Otherwise, there's no possible way to really do Addams on television."

The sitcom we saw was, in Coogan' view, watered down by the dulcet tones of the traditional family sitcom.

He still said that playing this version of Fester was his favorite role in his career.

"The series has to be written the way it is," Coogan explained. "I hope rabid enthusiasts forgive us our sweetness, but that's censorship."

What Coogan saw as censorship, the audience perceived as pure magic, especially when it came to what became everyone's favorite Uncle Fester bit.

As Uncle Fester, Coogan often literally lit up the sitcom by placing a bulb between his lips and amusing all the kids watching when it glowed from his internal electric current.

This oft-repeated bit even inspired a popular toy, first distributed in 1967, which, over time, became a collector's item worth more than 30 times what it originally sold for in comic books.

"Uncle Fester's Mystery Light Bulb," The News Journal reported in 2003, "piqued our interest" like no other Addams Family toy, even though it looked just like an ordinary light bulb.

Kids who ordered the toy knew the trick was a hidden flashlight fueled by a AA battery.

To pull off the Uncle Fester effect, all kids had to do was stick a piece of tinfoil in their mouths to form a connection between two points on the mystery bulb’s base that lit up the flashlight.

A simple trick, the effect was just as shocking to any suspecting onlookers as Uncle Fester's trick looked on TV.

The mystery bulb originally sold for just $2.00, but in 2003, some collectors were reportedly paying more than $75 for working bulbs.

Today, it's still rare to find the item listed, but you might be able to get yourself a working mystery bulb for about $20 on eBay.

In a way, these last remaining mystery bulbs form the last remaining afterglow of Coogan's legendary performance as Uncle Fester.

Coogan was proud that even though The Addams Family couldn't be as dark as his tastes would prefer as a fan of Charles Addams' work, the TV show at least did stand out among other sitcoms that you could say paled by comparison to The Addams Family.

"Allowing that we can't do what should be done [with the TV show], what is done is beautiful," Coogan said. "Our series is the only one on television in which the husband and wife are idyllically happy. And our family trusts its butler."