It could be that there's a construction going on nearby, or someone is intentionally making the tapping sound to get his attention. Another possibility is that it's just a random sound effect in the cartoon's world.
Maybe there's some outside noise that's reaching him. Or it could be part of a dream he's having.
Maybe there's something mysterious or dangerous outside that's causing the tapping and scaring him.
It could be that he had a lot of activities and needed some rest. Or perhaps he's sick and that's making him sleep.
The cartoon guy might be sleeping because he stayed up late last night. Maybe there's a reason related to his adventures or it's just a peaceful moment in the cartoon.
Maybe he's just super tired from a long day.
Well, a guy sleeping in a cartoon can have various meanings. Sometimes it shows a character's vulnerability or fatigue. Or it could be a setup for a funny dream sequence or a surprise when they wake up to something unexpected.
Maybe he's just had a really tiring day and needed to catch some z's.
It could be that the vacation was so relaxing that it made him sleepy. Or he might have stayed up late the night before and is catching up on sleep.
It could be that he has a blocked nasal passage or some breathing problem that's causing the snoring. Or, he just might be in a really deep sleep and that's how his body is reacting.
There are various cartoons that could feature such a character. Maybe one like 'The Soundless World' where the main guy has hearing difficulties and shows his struggles and achievements.
I'm not really sure. Maybe it's some kind of strange or symbolic representation, but it's hard to say without more context.