It is almost impossible for a person to change one's own caste during her lifetime.
Bhishma said, 'The status of a Brahmana, O Yudhishthira, is incapable of acquisition by a person belonging to any of the three other orders. That status is the highest with respect to all creatures. Travelling through innumerable orders of existence, by undergoing repeated births, one at last, in some birth, becomes born as a Brahmana.
The same chapter and its next chapter tell that it is impossible for some orders to attain Brahmanhood in the same lifetime. And also says that it takes a long time and multiple births for the individual in order to become a Brahman.
Although the two chapters say that changing one's caste in her own life is impossible, there can be some exceptions due to some reasons. Some people who changed their own caste in the same lifetime can be obtained from the following statement.
‘Viśvāmitra, Mātaṅga, Vaśiṣṭha, Nārada and others became elevated by special penances, not by birth.’
I want to know the names of others from the scriptures. What are the names of other persons from scriptures who changed their caste during their lifetime?