I am about to go to a congratulations-you-got-tenure party for a faculty member. The theme is the Sea Cucumber.
When I asked "why a sea cucumber?" the answer I got was:
The sea cucumber, in its larval stage, has a notochord (a rudimentary spine) and central nervous system (CNS), with which it propels itself through the ocean, finding food where it can and seeking one thing before it grows too old: a good place to stop. Having found such a place, it attaches itself firmly and permanently to that substrate, consumes its notochord and CNS, and filter-feeds for the rest of its life.