It's time for the weekly nature identification thread! Post pictures of plants, animals, rocks, or other cool stuff that you've photographed but can't identify, and I, along with anyone else who would like to help, will try and help you identify it. I'll be making some changes to it- most notably, I'll be using the SBD proceeds from this post to give out 
The Vampire Finch. The vampire finch, native to the Galapagos islands, is one of Darwin's famous finches. The vampire finch likely evolved its blood drinking habits to compensate for the extremely dry, arid conditions on its native islands- it gets most of its nutrients from nectar, seeds, and the like. You don't have to worry about it drinking your blood- it only targets other birds like the blue-footed boobie, which... really don't seem to mind, weirdly enough. The vampire finches likely started out pecking parasites off the larger birds, a valuable service, before transitioning to vampirism. [Image source]
Remember: The most important information you can give along with any photo to be identified is its geographical location. This narrows down the range of possibilities more than any other info you can provide.
Plants:
Along with the photo, add where you found it, the time of year, the approximate altitude, and any interesting scents or textures not caught in the photo.
Animals:
Along with the photo, add the location you found it, the time of year, the sounds it made, any interesting behaviors, and any other features not caught well in the photo.
Rocks:
Along with the photo, add the location you found it, a description of the terrain it was found in, whether it was attached to a rock outcrop or found loose on the ground or buried in the soil, a description of its texture (especially its grain size), and a description of its weight and density. Fossils are included in this category.
Fungi:
I will not be identifying mushrooms and fungi for the most part unless I can point to it and go "Yeah, that's poisonous." I will definitely not be identifying edible mushrooms. Mushrooms should really only be identified for foraging purposes in person and by an expert. If another contributor wishes to identify them, that's their call, but I encourage them to be similarly cautious. I might also identify a few fungi that are clearly not being looked at for the purposes of eating, but that'll be a case by case decision.
Bibliography: