American Vampire Finches

American vampire finches are a group of future descendants of Galapagos vampire finches that were genetically engineered to tolerate mammals, diseases, etc. They are now complete blood-suckers, with blood from birds and mammals being their only food sources, often drinking blood off of larger mammals like North American Neomastodons, predator dylanuses, etc, and birds like Hippostriches, groundbird, etc.