Prahlada, the legendary devotee of Lord Vishnu. But, you may ask why he was born as a Demon’s son, which was HIRANYAKASHIPU. But, there is a reason behind it.
Soma Sharma, a great devotee of Lord Vishnu, lived in a quite forest. He spend his entire life chanting Lord Vishnu's name. But, there are some rakshasas who distract Soma Sharma, on performing his Tapas. But, he remained indifferent. Then, when he was too old and at the time of leaving his body, he should think about Vishnu. But, at that time of leaving his body, he mistakenly thought of the Rakshasas beside him. And, he left his body. That's why on his next birth, he was born as a son of Hiranyakashipu.