Fizban’s Treasure of Dragons introduced a new ranger subclass: The Drakewarden. It originally appeared in an Unearthed Arcana article, and has seen some changes since the playtest version.
The Drakewarden is pretty great. The drake is nice and durable, it does decent but not spectacular damage, and it gains the ability to fly on its own eventually so it’s low-maintenance other than spending a Bonus Action to command it. Altogether it’s a very solid subclass. It’s roughly equivalent to the Beast Master with the Tasha’s updates, so I included a section detailing the differences.
For people consider a mounted combat built with the drakewarden, prepare to be disappointed. While you can ride the drake very effectively, it’s intelligent and therefore counts as a uncontrolled mount. It also takes its turn right after yours, which makes positioning yourself to attack a nightmare. We were so close.