There are several factors. Firstly, his physical description - tall and lanky with an unclear face - is very off - putting. Secondly, his behavior of preying on the alone and vulnerable at night is quite terrifying. And finally, the fact that he haunts desolate places adds to the overall sense of dread. People are already scared of such lonely and spooky locations, and his presence there just multiplies that fear.
His smile. It's not a normal, friendly smile. It's a wide, almost grotesque grin that makes people feel uneasy just thinking about it.
Maybe it's the fact that a lollipop man, who is usually associated with safety and helping kids cross the road, becomes something menacing. It's a subversion of the normal, friendly image we have of them.
The repetition and the mirror aspect make it scary. Just saying a name five times in front of a mirror is a simple yet spooky action that can lead to a terrifying encounter.
His height makes him intimidating. Being taller than normal gives him an imposing presence.
Maybe it's his appearance. If he has a tattered poncho and a haggard face, that would be quite spooky.
The muffin man is scary because of the rumors surrounding him. There are stories about people disappearing after going into his bakery, and the strange noises that come from it at night. Also, the fact that he seems so isolated and his muffins have an almost hypnotic allure that might be hiding something more sinister.
The unpredictability of the 'jangly man' makes it scary. You never know when he'll appear.
The noise he makes. The jangling sound is often associated with something strange or out of place. It could be a warning sign that something bad is about to happen.
The sound he makes. The jangling noise is really spooky. It gives the sense that he's always near but you can't see him right away.
In scary stories, the jungly man is often associated with the primal and uncontrollable forces of nature. He represents the part of the jungle that is wild and untamed. His existence defies the normal order of human society. He moves silently through the undergrowth, and his actions are unpredictable. For example, he might snatch a person from their campsite at night just because they are in his territory, which is extremely frightening.