Bestiality where the animal character is partially humanized (more than just by being able to speak). Usually this is when an animal that does not have a human-like face (e.g. a crab), is drawn with a face that is extremely human-like (e.g. sebastian_(the_little_mermaid)).
This is distinct from the bestiality tag, where animals are either not anthropomorphized or are minimally anthropomorphized (like being able to speak). For example, Balto from the animated movie Balto.
The most important distinction is that the anthro-bestiality is not in the default blacklist, while bestiality is.