Cut off a starfish's arm, and in some species that arm can grow a whole new starfish

Most starfish can regrow a lost arm as long as their central disc survives. But in a few tropical species, a single severed arm — if it still carries a fragment of the central disc — can regenerate an entirely new starfish from scratch, effectively cloning itself through injury.

— Wikipedia contributors, Starfish regeneration — Asteroidea regenerative biology