Cut each shrimp into 3 or 4 bite size pieces and save one whole peeled shrimp for garnish for each person you are serving.
Place the diced shrimp in a large bowl (glass is better). Next add the lime juice. Mix in the ketchup, RedBeards, Worcestershire, onion, chopped cilantro. Mix well.
Cover with plastic wrap and place the bowl in the fridge. Don’t forget to place the saved whole shrimp and cilantro sprigs for garnish in the fridge as well.
Refrigerate the shrimp mixture for an hour (45 min before adding the avocado).
15 minutes prior to serving, pit and cube the avocado. To do this, halve the avocado, remove the pit, run the knife down the length of the avocado to make at least 4 length-wise cuts, then cross cut the avocado to create medium size cubes.
Scoop the cubed avocado out with a spoon and add it to the shrimp cocktail and lightly stir it in to combine all the ingredients.
Place back into the fridge for the remaining 15 minutes.
Remove the bowl from the fridge.
Fill margarita glasses with the shrimp cocktail mix. Add one whole peeled shrimp to the rim of the glass and garnish with a sprig of cilantro.
If serving more than 4 people, use 1-1/2 pounds of cooked peeled shrimp. The 16-20 size works best.