Hermit crab
A crab living in a borrowed shell — a soft body depending on a casing that came from somewhere else.
A hermit crab in a dream is the dream's image of a soft body depending on a casing that came from another creature's life. The hermit crab does not grow its own shell; it finds one, occupies it, and moves on when it outgrows the size. The dream brings the hermit crab when something in your life — a role, a household, a public persona — is currently being inhabited rather than built, and the shape around you was not made for you. A hermit crab settled in a well-fitting shell is the dream affirming the borrowed arrangement. A hermit crab outgrowing the shell and exposed on open sand is the dream noting that the borrowed casing is no longer big enough, and the soft body must risk the open to find the next one.