The knight on horseback is a classic fantasy trope. Even the White Wizard himself had a famous horse companion. But the 5e core rules provide little in the way of support for heroic mounts. There are only a few equines ranging from 11-19 hp, which isn't enough to survive much beyond 3rd level when their riders are able to do more with them. And the core rules contains just a few 'monsters' suitable as character mounts. Why should a paladin, for instance, even bother to cast find steed?
This document aims to fill the gap by offering a wider range of both animal mounts (including more kinds of horses) and horse-like monsters across a wider range of CRs (to make them survivable across all 20 character levels). Additionally, it offers some templates and a concise system of feats for mounts to further distinguish and advance special steeds.