Grant Morrison believes the tires on the Batmobile are sustained by the collective human subconscious, which is in turn sustained by the observations and understandings of extra-dimensional super-beings. He also is (while quite a good comics writer) occasionally a bit of a lazy fucker who uses metafictionality as a crutch for substandard worldbuilding and characterization. We don't need Harold to be a thing, but we could have some handwaved super-science explanation pretty easily.
Also, see attached picture. Bulls are still cows, insofar as "cow" is a common term applied to cattle in general. You're quibbling, though. Why don't they just have cows and bulls as normal? Why have a "male cow"? The 8 year olds who play fucking Pokemon know cows and bulls are females and males. It's not uncommon knowledge even amongst fairly young or dumb kids, and if it were, one or two lines of casual dialogue would clear it up quick.