Divide the avocados, and use a spoon to take out the inside of the avocados.
Put the avocados in a blender.
Pour the lime juice in the blender, and mix together.
Whip the cream hard in a bowl.
Pour the avocado in the cream and stir slowly together to a mousse.
Divide the mousse in 4 serving bowls, and put them in the fridge for minimum 2 hours.
Before serving decorate with the shrimps on top of the mousse.