Galava Maharishi was a great saint and grammarian mentioned in the Markandeya Purana. The name of Galava Maharshi is also found in the list of teachers in Shukla Yajurveda. His name is also mentioned by Panini.
As per Markandeya Purana, once Galava Maharshi was oppressed by a demon. Ritadvaja, son of King Satrujita, came to the help of Galava. The demon was very powerful and could not be easily overpowered.
Sage Galava then gifted Ritadvaja a divine horse, which was presented to him by the Devas.
Riding on the horse, the prince defeated the demon.
Please note that there are several personalities in Hindu Puranas with the name Galava – one is a disciple of Sage Vishwamitra (Mahabharata Udyoga Parva); another is a son of Sage Vishwamitra; another is a yogacharya and a minister of King Brahmadatta of Panchala.