In a large skillet over medium-high heat, brown the ground beef. Crumbling the meat into up into small chunks. Cook until no longer pink.
Drain any excess grease. Add ½ cup salsa, water, and the taco spice mix. Bring to a boil and then reduce heat to medium and simmer for 5 minutes.
Now it's time to build the tacos! Start with a layer of taco meat, then lettuce, cheese and salsa. Place two large dollops of sour cream on each taco. Then top with a sliced olive. And just like that... Walla! You have fun Halloween tacos!