During my brief and entertaining stint at Pizza Hut when I was in high school, this abomination was on the menu. They were a pain to make, essentially requiring the cooks to stop everything else, get stuff out that you only used on these things and then put all of it up until the next time somebody ordered one.
As I recall it had two different sauces (one salsa based and one bean based) that both went on it, lettuce, tomatoes you had to chop, meat with taco sauce, onions, crushed taco chips. Little of that was out on the board. You had to go into the cooler to get it. It was a pain in the butt and our least favorite thing to make. It was, therefore, the subject of much experimentation and topping enhancement. Don't even try to imagine.
FWIW, I adored PJ Soles who starts that commercial off. I wanted her or somebody just like her.