Unknown animal - What could it be?
The animal is very suggestive for Dog whelk-like mollusc removed from its shell.

I try to mark the organs, do not rely on these marks as an absolut.


Testis
Renal vein
Gill
Mantle
Prostate
Osphradium


10 and others - digestive and reproductive systems, cannot mark precisely.


Digestive gland


source for comparing etc