A malformed specimen of Ensis leei Huber, 2015, with a dead specimen of Littorina littorea (Linnaeus, 1758) inside is reported upon. It is argued that the malformation of the bivalve was due to the intrusion of the littorinid. Despite this intrusion, that happened when the Ensis specimen had a shell length of c. 4 cm, the bivalve animal grew to a shell length of 12 cm. This is the first record of such a phenomenon.