1. Blend the Worcestershire sauce, onion, and crab into the cream cheese.
2. Line a small bowl with plastic wrap. Press the cream cheese mixture firmly into the bowl. Cover with more plastic wrap and chill at least 1 hour.
3. When ready to serve, remove the plastic wrap from the top, and place a chilled plate over the top of the bowl. Holding the plate to the bowl, quickly flip it over, and gently lift the bowl as you ease the crab ball onto the plate.
4. Serve with crackers and topped with cocktail sauce.