Fleshy
From Guild Wars Wiki
Fleshy creatures are, for the most part, organic (i.e. not constructs like Jade Armors, ethereal like Azure Shadows, nor skeletal like Skeleton Rangers). Most plants and most non-skeletal, non-ethereal undead are likewise considered fleshy creatures. Fleshy creatures are susceptible to Poison, Bleeding, and Disease, and leave exploitable corpses.
Non-fleshy creatures are immune to poison, bleeding, and disease, and do not leave exploitable corpses.
Note that some (but not all) bosses with skins of non-fleshy creatures DO suffer from conditions themselves.

