Brittlestar
Brittlestars are similar to sea stars in that they both have tubefeet. However, because brittlestar limbs are separately segmented as opposed to seastars whose limbs are all joined, brittlestars mainly use their limbs for transport whereas sea stars rely on their tubefeet.
Their legs are similar to a lizard's tail - they can shed them to avoid being eaten when a predator grabs hold. The leg then grows back - it is as if nothing ever happened.
However, unlike the lizard's tail, the Brittlestar's disguarded leg can grow into a whole new Brittlestar.
They've even learnt to pull off their own legs deliberately to reproduce - it saves them having to find a partner and forking out for expensive dinners.