Maybe it's expressing disagreement or showing that it doesn't like something.
The cartoon dog could be shaking its head because it's confused or trying to say 'no'. Sometimes it's just for added animation effect to make the scene more interesting.
The reason for the cartoon dog shaking its head might be to convey a negative emotion or response. It could be responding to a situation or another character's actions in a way that indicates its opposition or dissatisfaction.
Maybe it's expressing disagreement or showing that it's confused.
It could be that the comic dog is responding negatively to something in the story. Maybe it doesn't like the situation or the other characters' actions.
Maybe it's scared or excited. Sometimes dogs shake when they have strong emotions.
Maybe he's not happy with something or expressing disagreement.
Maybe he's not happy with something or doesn't agree with what's going on.
Maybe it's because it's cute and funny. People just love seeing dogs do funny things like that.
Maybe he saw something he really didn't like or thought was bad.
Maybe he didn't get what he wanted or expected.
It could be that the character doesn't like the idea or situation presented. Or perhaps it's responding negatively to a request or suggestion.
You can start by sketching a simple oval for the head. Then, draw two lines for the neck. For the shaking motion, show one side of the face slightly tilted and the eyes looking in that direction.