Sea cucumber
A marine animal named for its cucumber-like shape, with short tentacles at one end. Not readily available fresh in the United States, but available dried in Asian markets. Dried sea cucumber must be soaked in water a minimum of 24 hours, and will double in size and take on a gelatinous quality. It's rather rubbery and is most often used in soups.
Plural
Sea cucumbers
Season
available year-round