Gaganganja Bodhisattva is also one of the great bodhisattvas among the group of eight bodhisattvas. Gaganganja Bodhisattva is either yellow or red in colour. Gaganganja Bodhisattva symbol is a Kalpa tree.

In some instance Gaganganja Bodhisattva is described as golden yellow in colour. Gaganganja Bodhisattva holds the vajra in his left hand while the right is pointed to the sky. In Tibetan Kanjur a special sutra dedicated to this Bodhisattva is extant with the name of Gaganganjasutra.

According to the Swayambhu legend Bodhisattva Gagan-ganja is said to have appeared in Kathmandu valley to bless Prince Gokarna who was a great sinner indulgeing in harsh and immoral speech with his father Vrisakarna.

As a result, the king sent him into exile. The king himself could not bear the evil deeds of his son and passed away with great despair. His spirit was roaming as a ghost for the same reason. He was not able to secure a happy rebirth. Later the prince also underwent torturous experiences as though from a hell realm in exile. Upon realizing his misdeeds, he later performed an act of penance in Punya Tirtha near Gokarna. Bodhisattva Gaganganja appeared in front of prince Gokarna and instructed him to perform the necessary death rituals and offering ceremonies in honour of his deceased father. Bodhisattva Gaganganja told him that this act would definitely be helpful in securing a good rebirth for his deceased father. Since then Nepalese people are continuing to offer pinda dana to their deceased fathers in the day of Shravan Krishna i.e. new moon day of July–August. A monument dedicated to Bodhisattva Gaganganja still exists to this date in the Gokarna area where hundreds of devotees perform Astamivrata and ritual offerings.