Sabellidae (feather duster worms) are sedentary marine polychaete tube worms where the head is mostly concealed by feathery branchiae. They build tubes out of parchment, sand, and bits of shell. Geometry in Nature by Esteban Toré
Multicolored Nudibranch Photograph by Mohammed Alsaleh, My Shot Generally oblong in shape, nudibranchs can be thick or flattened, long or short, ornately colored or drab to match their surroundings. Some max out at a quarter of an inch millimeters)
mirkokosmos: This is the caterpillar of the Pink Underwing Moth and is commonly referred to as the Skull Caterpillar. It is found in certain regions of Australia and is listed as endangered. As an adult moth, it will have a wingspan up to 170 mm.