Bring water and butter to boil, lower heat
Stir in flour until thickened and pulled away from sides of pan, let cool to room temperature
Beat in egg one at a time (you can use whisk balloon but that is tiring IMO), until mixed well
Pour dough into piping bag and pipe following the templates
Bake at 350 F for 20 mins for the body, and 10 mins for the neck
Take one body and slice (easier cut with kitchen scissor) horizontally (halved horizontally)
Leave one side as is and fill/pipe the filling, and cut the other side into wings
Push wings and neck onto cream and your swan is ready