Yes, basically
Currently I have two entities on my screen that are accessed via static methods and I wanted to make it seem like one was replaced by a new one, kinda hard to explain.
However, as it turns out, I was thinking waay too complicated and using animations is the obvious way to go here, especially because the entities should become animated in the future anyways.
Sadly, I couldn't manage getting it to work. I created a method called set() which is intended to replace the existing Singleton-Entity with another one. It looks like this: 
However, it does nothing. The instance and animationName objects will be set correctly but no animation plays. I thought that re-setting the instance possibly caused a problem of the screen and the background code not talking about the same instance anymore, if that makes sense, but as I cut the constructor and used a setter instead, nothing changed.
I also tried adding the animation to the constructor and only calling the play() method from other classes but it didn't help either. At this point I don't know what to try anymore, do you have another idea what I could do or what the problem might be?