What is this strange horned, slug-like coral reef dwelling creature? On the first episode of BBC's Blue Planet II they visited a coral reef and showed some odd reef-dwelling creatures as part of their establishing shots, but they did not identify the creatures. What is this odd horned, slug-like creature? (Sort of like a slug with legs?) ![Sea Blob]( I tried a Google reverse image search and it very 'helpfully' identified it as "Documentary film". So close, yet so far. * * * Disclaimer: This question was split off from another question since the original was effectively two questions.

Here is your animal in Blue Planet II trailer:

![enter image description here](

This is a sea cucumber (Phylum Echinodermata, Class Holothuroidea).

More specifically, this is a sea cucumber from the Species _Pearsonothuria graeffei_, the Graeffe's sea cucumber.

Here are other images of _Pearsonothuria graeffei_ for comparison:

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Sea cucumbers have an antero-posterior elongated body, as you can see in this image of the whole animal:

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Those black structures you see are the tube feet, a distinctive feature of Echinoderms.

Here is a detailed image of the tube feet in _Pearsonothuria graeffei_ :

![enter image description here](