Roughly chop one half of shrimps and leave aside.
Place the rest of shrimps in a food processor. Add onion, green onion, beaten egg, bread crumbs, parsley, cilantro, salt and pepper. Pulse all together until the mixture is well combined.
Add in the chopped shrimps and stir.
Form into 4 patties with your hands.
Heat up the oil in a frying pan over medium heat and start frying the patties. Cook each side for 4-5 minutes. Once cooked, leave the patties aside on a paper towel to drain excess oil.
In a medium size mixing bowl combine yogurt, mayonnaise and grated garlic. Drizzle with lime juice and season with salt and chopped cilantro.
Cut burger buns in half. Take the bottom half and cover it with some chopped lettuce. Add a spoonful of garlic sauce. Place a shrimp patty and a few slices of avocado on top. Spread another layer of sauce and cover with the top burger bun. Serve with fries and a dip bowl with the remaining garlic sauce!