Weenie Tots refer to the food product eaten primarily by Al Bundy, as well as the factory that produces them.
The brand itself is owned by Tot Industries, which is owned by Earl and Pearl Tot; one of the heirs, their son, Lonnie Tot, attempts to marry Kelly Bundy in the series finale, Season 11's "How to Marry a Moron (Part 2)".
When Peggy asks what exactly is a Weenie Tot, Al is surprised and then proceeds to tell her:
"What's a Weenie Tot?!...Peg, a Weenie Tot is a delicious little hot dog type meat, wrapped in a breaded shell and deep fried in pure lard...its nature's perfect food."
When Al and Kelly visit the factory for her audition to be the next spokesmodel, a wheelbarrow marked "Beaks N Claws" is rolled by in front of them, while she asked if he had noticed that there were no trashcans outside. It is also implied that, in addition to the beaks and claws, the meat may also contain the severed hands of some of the factory workers.
It can assumed that the hot dog meat in Weenie Tots is likely a mixture of pork, beef, and chicken parts as well human hands. As the hot dog is wrapped in breading and deep fried in lard (rendered leftover fat taken from the abdomen of a pig), it can be safely assumed that Weenie Tots mostly taste like pork, given all of the pig-derived ingredients in them.
On the box of Weenie Tots, it informs the consumers that there is no nutritional value, its not real food and warns: "Do not expose to air. Will accelerate disintegration process". Peg decided not to heed the warning and proceeds to open the boxes to find a winning scratch off ticket, literally turning all the exposed Weenie Tots into dust by the time Al returns home from work. This also shows that the product is not shelf stable.
Al has noted that he loves Weenie Tots as much as he loves pizza. One of his reasons is that they cause him to go to the bathroom.
Outside of the show, this is would most likely be known as "Pigs in a Blanket", a simple hors d'oeuvre consisting of a bite-size sausage or hot dog (sometimes topped with a slice of cheese), wrapped in up a croissant, phyllo or biscuit dough and usually baked.
References on Married... with Children
Weenie Tots are first referenced in the 5th season episode "Weenie Tot Lovers and Other Strangers" as Kelly tries to be the next Miss Weenie Tot Spokesmodel and win a year's supply of Weenie Tots for the family.
In "Love Conquers Al" during a couple's exercise with Dr. Richelieu, Ephraim Wanker tells the doctor that he doesn't want to participate out of fear that Peg's Mom will bite his fingers off. He then tells Ephraim, "If you can't reach out to her with a weenie tot, how will you reach out to her with your heart?!" and presents a bowl full of Weenie Tots to him. Unfortunately, for Ephraim, as he tried to do what the doctor ordered, he ended up with his fingers bit.
In "The Joke's on Al", June gives Al a large bowl of Weenie Tots that Bud and Kelly take while June discusses spending the night at the Bundy residence. After June heads upstairs, Al reveals his plan to seduce June and then tells the kids to dig in and eat like royals.
In "The Stepford Peg", a platter with Weenies Tots is seen on the coffee table in the Bundy living room during the wrestling watch party. Later, Peggy comes down and asks if she needs to freshen up the Weenie Tots. Then, after Peggy regains her memory during sex with Al, he screams to the NO MA'AM members downstairs to "Grab your Weenie Tots and run for your lives!", with Bob Rooney picking up the tray as he and the others run out.
In "Live Nude Peg" when Peggy talks to Marcy about her new job as Jasmine, she mentions that she didn't reveal her identity to Al after he came home, as she said that he jumped on her "like a human weenie tot!"
Weenie Tots are also seen in the Season 11 episode "Damn Bundys" as The Devil attempts to use them as a form of torture for Al when he goes to Hell as the Weenie Tots will confine a soul to the bathroom for eternity, only to find out that Al loves Weenie Tots and going to the bathroom is the reason Al loves them so much.