These little goobers are called peanut worms, or sipunculids. Sipunculids are in their own phylum Sipuncula (that’s a pretty high level of taxonomic classification), so while their unsegmented bodies make them look like other marine worms (phylum Annelida), they are not directly related.
Sipunculids are pretty fascinating to watch because they can invert their long proboscis to bunch up (like the little peanut-look-alike on the far left), or extend it by essentially turning inside out. These specimens were just some of the great diversity of critters I found poking around in a kelp holdfast. Now the question remains: would you like those salted or unsalted?