SB 5.20.39
tad-uparistac catasrsv asasvatma-yoninakhila-jagad-gurunadhinivesita ye dvirada-pataya rsabhah puskaracudo vamano ’parajita iti sakala-loka-sthiti-hetavah.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
On the top of Lokaloka Mountain are the four gaja-patis, the best of elephants, which were established in the four directions by Lord Brahma, the supreme spiritual master of the entire universe. The names of those elephants are Rsabha, Puskaracuda, Vamana and Aparajita. They are responsible for maintaining the planetary systems of the universe.