Lobster isn't cheap, so you may be inclined to eat every last bit to get the most bang for your buck. Well, before you do, consider the health risks associated with one part in particular: the tomalley. 

Though it has a creamy texture and adds flavor, the tomalley raises concerns, says Barton Seaver, director Of Harvard’s Sustainable Seafood and Health Initiative.

The soft, green mass acts as the lobster’s liver and pancreas, so you can contract paralytic shellfish poisoning if the lobster ingested an infected bivalve, he says. (Don't worry, the meat is still safe to eat.) So while some lobster aficionados consider it a delicacy, it's best to leave it alone.