Given the question: Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Pupa (gastropod) -  Pupa is a genus of small sea snails marine gastropod molluscs in the family Acteonidae. The genus is named Pupa because the shell of these snails resemble an insect pupa in overall shape. The animal has a large headshield with a deep median slit separating it into two posteriorly projecting lobes.
The answer is:
Animal