The link between the energy of Kundalini Yoga and the serpent of the Bible is described very clearly in the book "The Secret Doctrine",
This book was written by Helena Blavatsky (known as the mother of modern spirituality), who traveled all over the world to find the ancient wisdom of different peoples. The book "The Secret Doctrine" was published in 1888, at a time when the term "Kundalini Yoga" was still unknown in the West.

Helena Blavatsky is called the mother of the New Age movement and the mother of modern spirituality because she was the main actress in the writing and popularization of esoteric, New Age and occult resources. She writes under the dictation of Maitreya, the Masters of Wisdom. It is in fact she who will teach for the first time on the subject of the Masters of Wisdom. She will also teach on ancient mythology, Hinduism, reincarnation and karma, the revelations of the Egyptian God Toth, astrology, sacred mathematics, chakras, Atlantis, esoteric knowledge, Kabbalah, the higher self, magic, yoga, mediumship, the third eye, the Christic term...

It will put forward an esoteric interpretation of the Bible and will speak about a falsification of the Bible in connection with the councils for example. All these subjects, we find them today in the modern spirituality that is the New Age.