There are some examples in which animated characters look directly at the viewer with or without quotes.
Can we call these "breaking the 4th wall" while the characters are non-living?
The Lion King (1994):
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Breaking the 4th wall is not a "character" looking at the audience. It's the acknowledge of the existence of audience by the work thus incorporating it in it's own existence.
Breaking the 4th wall is for that - to break the invisible wall and merge both worlds. It's not the decision of the character to do that (because they don't exist) or an actor himself but the creator.
The director will/can, as a part of artistic decision, to allow it thus expanding their "world represented". For example to reach and use "our" world as tool. You see (for example) a play in theathre can be narrowed to one room. If you brake the wall you suddenly have whole building to use. You don't have to create the world your characters live in because it's the same your audience live in.
In case of animations breaking 4th wall is the acknowledge that they are animation. TO quote Jessica Rabbit
I'm Not Bad, I'm Just Drawn That Way!
The self-consciousness is what does it. Not looking at the camera. Looking at the camera in movies is advised against because it show acknowledge of the camera itself in the "world represented" not the existence of viewer.