Peak D&D world building is where domesticated animals have been affected by fantastical phenomenon just like humanoids. I'm talking about horse breeds with minor magical traits: Steeds from the feywild that can go ethereal and require riders to use enchanted saddles to stay on them. Horse bloodlines tainted by the shadowfell that have resistance to necrotic damage but have sunlight sensitivity. Not full on Unicorns or Nightmares or Pegasi but like... do you get what I'm say? It's good stuff, right?
Hi! oh heck yeah that sounds dope! Next time I run a game I might put some of those kinds of steeds in 👀
~ Larn