This is a popular Puranic tale. In life, someone has a particular configuration of planets which bring evil, due to the malefic influence of Saturn (shani). So it is called Shanichari or Panoti. For some, it lasts for five years, and for some it lasts for seven & a half years. Read below, who does and who does not suffer the great misfortune caused by Saturn.

Once, Shanichari approached and spoke thus to Lord Rama: “O Raghuvar, come and fight with me. I have fought with many persons and have been causing many persons to flee and wander. However, the other planets say they will acknowledge my power only after I defeat Lord Rama. Hence, you come to fight with me.”

Lord Rama said, “You are a female. How can I fight with you?” Shanichari said, “In that case you have to accept defeat.”

Lakshmana said, “O brother, how can we accept defeat?”

Lord Ramaji said to Shanichari, “Go and fight with my attendant. You register a victory over my disciple. Defeat of my disciple is akin to my defeat and his victory is akin to my victory.”

Such verily is Lord Rama. He has a hope in his heart that his disciple too should become Rama (like him). The Lord sent Shanichari to Hanuman.

Shanichari went to Hanuman and said, “Lord has sent me to you. I have confounded many persons. Now it is your turn to suffer misfortune. In this fight neither your roars nor the blow of your tail will work. Showing your mace will not work. I am very strange. Come on.”

Hanumanji said, “Well, my Lord has sent you, and my winning will bring victory to my Lord. If I don’t accept your challenge it will mean that my Lord is defeated and that will bring disgrace to me. But see, how can I fight with you? I don’t touch any female because I am a Baal Brahmachari (a celibate from infancy).”

Now what to do? After giving it a lot of thought, Hanumanji said, “Since the Prana (life-force) of the entire body is focused in the head. So you don’t touch my body, just touch my head.”

Panoti climbed onto Hanumanji’s head. When the Panoti comes, it ascends onto the head and bewilders the brain. Hanumanji thought: ‘Now she will bewilder my brain.’

Hanuman went into solitude. His bewildered brain said, “Go away from this place.” Panoti said, “Let us go.” Hanuman said, “I shall go but before that let me hurl the Om mantra at you. Hanumanji chanted Om…. He lifted a hill and placed it atop his head.

Panoti squealed, “Remove this hill, I am dying.”

Hanuman said, “I haven’t even touched you.”

“You did not touch, but crushed me. Release me. I shall not come again.”

“You came to defeat my Master. The knack is given by my Master (Lord Rama) that whenever you face any disturbance or bewilderment, chant Om and place the hand on the head. Since you, a female, are seated on my head, I cannot touch you with my hand. So I have placed just a hillock.”

“Leave me, leave me. OK you win.”

“Should I put you down?”

“Yes, let me down.”

Hanumanji removed the hill from his head, and said, “Go, jump down.”

Panoti jumped down and said, “I am pleased with your power and Guru-Bhakti. I wish to give you a boon.” 

Hanumanji said, “Go away. You are defeated. Your boon is of no use to me.”

“Well, I am not eligible to give you a boon but I am worthy of obeying your command. You give some command to me.”

Hanuman said, “You shall never sit on the head of the person who is of strong disposition like me, who remembers me, who performs the duty of a servant towards his master. If you sit on their head, you will crumble into pieces.”