Hi and thank you for answer me.
I tried your method (changing a few things) and it worked fine for the player to become a mouse, but when I use it backwards it gave me the following error:
Parser Error: Can't preload resource at path: res://Objets/Player/Player.tscn
There is the code:
old_node = Player
var nextNode = preload("res://Objets/Player/Player.tscn")
var new_node = nextNode.instance()
new_node.name = old_node.name
new_node.position = old_node.position
How can i solved this?