I ran into some horsies in the swamp called Diremares and
Frightmares. Strange creatures they are. They cast a couple
spells then retreat, retreat, retreat. I can't kill 'em cause
I can't catch 'em. Well I did manage to kill one only because my
Ranger did a KO. Why do they continually retreat? Oh I know.
They're scared of my party. Yeah that's it :)
Seriously though, any tricks to it? None of my "holding" spells
has an affect on them.

happy hunting

Helix

Persistence works :D - and while not gauranteed, running the other way sometimes gets them to chase you instead.

I have only run into them once, and have traversed the whole swamp.
I saw them my second time around, i followed them untill i cornered them over on the west side of the map they went through a small space between the rock and the lake.

then i just unloaded they were pretty weak.
but they looked cool.
i got the diremares

The Fightmares cast fear spells, and they are also very easily frightened of just about anything. Keep on chasing and retreating and eventually they will stop and fight again, once they become unafraid again.

I actually run away when I see night mares, one time they cast rears on me and my party ended up hacking each other to pieces :(

I had the hardest time with these various unicorns. Unless you are well protected by magic defences, they are real survivors at your expense! I run away from them. I'd wait 'til I'm greater than level 12 or higher. I'm not sure if there is a good strategy beyond chasing them and beating them up with close range weapons.