Start by preparing the cooked lobster mixture. Combine langostino tails or chopped lobster meat with Greek yogurt and sriracha in a bowl. Adjust the sriracha to your preferred spice level.
Thinly slice the carrots and English cucumber into matchstick-size strips. Slice the avocado into even slices.
Fill a shallow dish with warm water. Dip one rice paper wrap into the water for about 10 seconds, just until it softens. Be careful not to over-soak, as the wrap can tear. Lay it flat on your work surface.
Place a nori sheet on top of the softened rice paper wrap. This double layer provides structure to the roll. Spread a spoonful of the lobster mixture across the bottom third of the nori sheet. Add a few carrot sticks, cucumber strips, and avocado slices on top.
Using your hands, carefully lift the edge of the wrap closest to you. Gently roll it forward, keeping the fillings tight but not squeezing too hard. Tuck in the sides as you roll to create a neat, cylindrical shape.
Use a sharp knife to slice each roll into bite-sized pieces if desired. Or leave each as a sushi wrap.