An elephant's trunk has no bones and roughly 40,000 muscles

Unlike a limb built around a skeleton, an elephant's trunk is a pure muscular hydrostat — the same structural trick an octopus arm or a tongue uses — packed with an estimated 40,000 individual muscles and no bone at all. That's what lets it pick up a single blade of grass with the same organ strong enough to rip down a tree branch. Biomechanists use elephant trunks and octopus arms as the two classic examples of this design.

— William M. Kier and Kathleen K. Smith, Tongues, Tentacles and Trunks: The Biomechanics of Movement in Muscular-Hydrostats — Zoological Journal of the Linnean Society, vol. 83 (1985)