Cut the avocados in half and remove the pits. Carefully scoop out a little bit of the flesh to create a larger cavity for the filling. Set the avocado halves aside.
In a mixing bowl, combine the cooked shrimp, diced cherry tomatoes, chopped red onion, and cilantro.
In a separate small bowl, mix together the mayonnaise, lime juice, garlic powder, salt, and pepper.
Pour the mayonnaise mixture over the shrimp and vegetable mixture. Stir gently until everything is well combined.
Spoon the shrimp mixture into the avocado halves, filling them generously.
Serve immediately, or chill in the refrigerator for about 30 minutes for a refreshing treat.