So someone edited the chimera tag recently and I noticed that it said it was a human animal hybrid. This is not what a chimera is. A chimera is a mix of, if I remember right, 3 creatures each with heads, goat, dragon, and lion, and is a specific creature.
Chimeras beyond that are not "human hybrids" they are other animal hybrids in mythology, each with features that can be seen from the respective animal. Humans aren't considered animals and so would never be mixed in as a chimera in mythology.
Medically a chimera is anything that naturally has parts that from a different genetic thing. For example, most women are chimeras, shown by having splotchy skin patches where the other person's(?) genetic cells are seen. Female calico cats are chimera, their 3 fur colors owing to the fact that 1 of the fur colors belongs to cells from a genetically different cat.
The only time when the term "chimera" is used to mean human-animal hybrid that I am aware of is in Full Metal Alchemist. That being the case, i don't think that the tag should specify human-animal hybrids (or include them at all). Or there needs to be different tags for these things... or something cuz there are 4 things that chimera refers to, the least accurate 1 being used with the tag.