There are seven Seers, Rishis in Sananatana Dharma.
These seven Rishis are called Saptha (seven) Rishis.
These Rishis are Eternal and they do not die even at the time of the Dissolution of the Universe.
But the Rishis change for every Yuga(aeon)
For the present time frame called Kali Yuga, these are the Saptha Rishis.
Kasyapa and Angirasa.
One of the least known Rishis is Kutsa.
Kutsa who traces his ancestry to Angirasa is mentioned in all the four Vedas, a rare honour.
He authored Sukthas in The Rig Veda but refers it to hos ancestor Angirasa as a mark of respect by callimg it Kutsa Angirasa.
As an aside it may be mentioned that the Great Acharayas never attribute their works directly to themselves.
They refer to their ancestors, as in the case of Kutsa or to thier Guru.
Following the later tradition Adi Shankaracharya attributes every work of his as,
‘Ithi Govinda Bhagavad Pada Shisya’
Kutsa also contributed 65 sukthas to Sri Rudram on the Yajur Veda.
He was a close friend of Indra, the Chief of Gods( devas)
He was a mirror image of Indra.
there is mention of a conversation between Sage Vamadeva and Indra which illustrates how Kutsa and Indra were not only intimate friends, but were also ‘look-alikes’ — so much so that at one point, Indrani herself could not tell them apart- Rig Veda 4.6.10
Kutsai was the son of a Rajarishi named Ruru. Indra helped Ruru by decimating his enemies, and he invited Kutsa to Indraloka to celebrate the victory. Once, Kutsa fell into a deep well, and Indra came running to save his friend- Rig Veda10.40.6.
Rig Veda106.6 there is a suktam consisting of seven mantras. Although Kutsa Rishi discovered this suktam, he named it in conjunction with his guru, Angirasa, as the Kutsa Angeerasa.
In Panini’s Ashtadhyayi, he is mentioned as an old acharya. He is described as worshipping Agni in different forms, addressing him with different names.
The Prokshana Mantra
‘Om Bhoo, Om Bhuvaha, Om Suvahaâ”
is by Kutsa.
Despite Kutsa Rishis strict observances, however, it is said that he once made a mistake in pronouncing a Veda mantram, and for this he was cursed to be a frog in a well. Once his period of atonement had passed, Veda Purusha told him that even while he was a frog, he would remember his previous birth and could be relieved of the curse if he did penance in a pushkarani (holy waters), praying to Soundararaja Perumal at Valmiki kshetram for 48 days. This the Rishi did, the curse was released, and he regained his former body.
The Valmiki kshetram referred to here is Thiru Anbil, which is situated 5 miles east of Lalgudi, in Tiruchy District of Tamil Nadu. It is the birthplace of the great sage, Valmiki, and is one of the 108 divya kshetrams.