Pick out a few of the nicer looking shrimp and set them aside for garnish. Coarsely chop the remaining shrimp.
In a small food processor, blend the cream cheese and mayonnaise together until smooth. Add the lemon zest, juice, mustard powder, garlic powder, salt, and pepper. Process until smooth.
Scrape the mixture into a bowl. Stir in the chopped shrimp and green onion. Add a dash or two of hot sauce. Season to taste with salt and pepper.
Transfer the dip to a small serving bowl and garnish with the reserved shrimp and chopped green onion. Serve with fresh vegetables, potato chips, crackers, fresh bread, etc.