Blubber is a thick layer of vascularized fat found under the skin of all cetaceans, pinnipeds and sirenians. Description Lipid-rich, collagen fiber-laced blubber comprises the hypodermis and covers the whole body, except for parts of the appendages, strongly attached to the musculature and skeleton by highly organized, fan-shaped networks of tendons and ligaments. It can comprise up to 50% of the body mass of some marine mammals during some points in their lives and can range from a couple of i… (More on Blubber)