Presiding over the ringing of the opening bell at the NYSE was the Spanish-speaking, burrito-eating Chihuahua that hawks fast food for Taco Bell Corp., a unit of Tricon Global Restaurants Inc. (NYSE:YUM - news), up 4/16 at 33-15/16. The pint-sized pooch was on hand as a marketing gimmick to launch a new ``freshly fried'' Nacho chips dish.