You must keep a reference to an Actor, or else it will self destruct and become static geometry.
Once your init function finishes, “butterfly” goes out of scope and there is no longer a reference.
The easiest way to do this is set it as an attribute of your class (use “self”).
Is there a reason why you would not want to keep a reference to the Actor?
If it is just for background decoration or something like that, you might want to keep a list of Actors, for example: