- Yashoda: She was shown a visual of the entire universe inside baby Krishna’s mouth
- 100 Kings captured by Jarasandh: When Bhim killed Jarasandh with Krishna’s guidance, these 100 kings were set free and shown the divine ‘Chaturbhuj’ (4 armed form) of Krishna
- Sage Muchukund: After defeating Kalyavan demon with the help of Sage Muchukund, Krishna showed him ‘Chaturbhuj’ form.
- Hastinapur sabha: When on a peace mission from the Pandavs to the Kauravs, Sri Krishna displayed his ‘Virat-swarup’, to frighten and convince the sabha members to accept his peace offer.
- Arjun and Sanjay charioteer: In the Bhagvad Gita he was shown the complete Vishvarup of Krishna.
- Yashoda
Yashoda was the adoptive mother of baby Krishna. Krishna’s biological parents were captive in the jail of King Kansa.
One day, baby Krishna was sitting on the riverbanks as his mother attended to some task in the river. Bored, the baby Krishna started scooping fistful’s of mud into his mouth. When Yashoda saw him, she was shocked and angry. She took the boy home and started washing his mouth.
She told Krishna to open his mouth so she could wash out the dirt. Krishna refused. Finally, when he opened his mouth, Yashoda saw the entire universe inside. She saw the 9 planets, swirling stars and divine visuals. She was mesmerized. But suddenly, the cosmic vision vanished, and all she remembered was her baby having eaten mud. - 100 Kings captured by Jarasandh
Later in life, when Krishna grew older and established the island-kingdom of Dvarka, he was the enemy of a powerful Shiva-devotee king named Jarasandh.
Some time later, Krishna motivated his cousin Yudhisthir to cinduct the Rajasuya yagna. However for it’s success, he would have to conquer all of Bharatvarhsa’s kings including Jarasandh.
Krishna, and Yudhisthir’s brothers Bhim and Arjun went to Jarasansh and challenged him. With the guidance of Krishna, Bhim was able to defeat him at a wrestling match, and even kill Jarasandh.
Jarasandh had 100 kings in his captivity, which he intended to sacrifice to Shiva in exchange for the boon of invincibility. Krishna ordered the release of these captured kings and showed them his ‘Chaturbhuj’ form, having 4 arms holding a conch shell, mace, lotus, and Sudarshan chakra discus. - Sage Muchukund
Muchukund was a king of the Solar dynasty who helped Lord Indra in defeating the demons in a long battle. Tired, he asked for the boon of resting without being disturbed. Muchukund was given a cave to sleep in and he was blessed to see a vision of God when he awoke.
Krishna knew that the only way to defeat an enemy of his named Kalyavan was not by the use of weapons. Krishna fled the battlefield, and lured Kalyavan into Muchukund’s cave.
Kalyavan thought he saw Krishna sleeping inside the cave, when really it was Muchukund. When Kalyavan kicked Muchukund thinking he was Krishna, the king awoke and the power which had collected inside his eyes (because he had them closed for many centuries while he slept) burnt Kalyavan to ashes.
Explaining the events and who he was, Krishna thanked Muchukund for killing Kalyavan. Then, as promised by the gods, Krishna showed him his divine form— the ‘Chaturbhuj’. - Hastinapur Sabha
War was almost declared between the Pandav princes and Kaurav princes of Hastinapur due to a long dispute between them. Krishna, was on the side of the Pandavs due to their righteousness. However to avoid the destruction of a war, he decided to go on a peace mission to Hastinapur, to try and convince the evil Kaurav princes to accept a peace offer.
However, when Krishna presented his arguments in the Hastinapur sabha, no one was able to convince the evil Duryodhan (eldest Kaurav) to compromise. Finally, Duryodhan planned to capture Krishna as a punishment.
In a final attempt to scare Duryodhan from the path of evil, Krishna revealed his cosmic form— the ‘Virat swarup’ in which he contained within him the entire armies of Dvarka, the Pandavs, the gods, the planets, and other celestial bodies. He had thousands of arms and in them various weapons. Krishna even gave sight to the blind king of Hastinapur so that he may witness this cosmic form aswell.
However the stubborn Duryodhan called it a magic trick and ended up dying in the war. - Arjun, and Sanjay charioteer in the Bhagavad Gita
This is perhaps the most popular instance.
Just before the war between the Pandav’s and Kauravs, the third Pandav Arjun, who was also a great archer and Krishna’s best friend, asked Krishna (who was Arjun’s charioteer) whether this war was ethical or not.
Krishna revealed the vedic wisdom and philosophy to Arjun trying to convince him to fight the war for justice. Thus dialogue between the two came to be known as the Bhagavad Gita. This dialogue was also overheard by Sanjay, the charioteer of Hastinapur’s king who was given divine sight in order to narrate the war’s events to his king.
During this philosophical discourse, Krishna reveals to Arjun his Vishwarup— his ultimate cosmic form. In this, Arjun sees the entire universe, all its people, gods, weapons, elements as a part of Krishna. Krishna has thousands of arms, thousands of heads and his form is both terrifying and beautiful. Arjun gets frightened and asks Krishna to revert to his normal human form