so youre saying its alright me and you get married

I can't believe I'm still surprised that some people don't know what Anthro is.
They're human-pony hybrids, usually made so for the sake of either fetishistic efficiency, or to make the characters more recognizable.

This chart gives a good overview, but there's a LOT of gray area in this sort of thing.
There's a solid couple of missing links between 4 and 3, namely "pony colored human with equine head", and I can't even begin to delve into the shades of gray between 2 and 3.
And there's offshoots not even listed on the chart, like the ones that for some reason have only three digits per limb, or the disturbing incarnation which is a human with an equine head, but forehooves. Not hooves on their legs, those are feet, but on their arms are hooves.
Horrifying.

I hope this was informative! And slightly disturbing, because let's face it, we all have a good time discovering the eldritch creatures of the internet.