Gulf Ghost Crab (Hoplocypode occidentalis, french: Crabes fantômes). It is very hard to spot, they blend in very well. (971k)
Here are the pictures of Gulf Ghost Crab (Hoplocypode occidentalis) with links to the pages on which they appear, links to the full sized picture, and the description of the picture with links to the entry in iNaturalist (inaturalist.org)
All pictures are © Dr. Günther Eichhorn, unless otherwise noted.
Costa Rica Nature
Dr. Günther Eichhorn Travel Website
Soaring website