UO Second Age

Taming mares: Nightmares are easier to tame than wyrms because the New Lands provide more opportunity to keep yourself distanced from the mare. They have a very large HP total — on the order of 1000. Their breath causes about 50 points of damage each time (meaning they're tougher than a drake). They sound like a dragon when they let loose and it's not uncommon for them to fall over on their side when they let go with it. If you've never seen this, it can scare you when you're using a tamed one to fight with because your first impression is that it's just been killed! They have magic, I've not seen anything greater than Lightning cast by them (although they can dispel). They seem to have roughly equivalent magery to that of an old fire elemental.