limpet

Any of various gastropods with a conical shell shape patelliform and a strong, muscular foot that they use to create strong suction to cling onto rocks or other hard surfaces.

Someone clingy or dependent; someone disregarding or ignorant of another's personal space.

He stuck to me like a limpet all day!

To gather limpets.

Mother visited the little cottage over the hill, and found Lisette's story to be quite correct; and many times the Frenchwoman blessed the day when Margie went limpeting and Lisette lent the old knife to the golden-haired little English lady.

Razor-fishing, sand-eeling and limpeting used to be popular activities but have declined in importance.