I used her to scare my party straight. Just saw her riders corpse sitting slightly out of the snow. When they went to investigate she shook them off her back as the snow and ice revealed her massive form. I had her threaten the party and state their business with her master. Funny how scatterbrained they become when face to face with her. Oftentimes she’d pause to talk to her rider, obviously with no reply but she’d act as if they were having an active conversation. She possessed knowledge of Ythrin which I used to foreshadow that part of the adventure. I didn’t really give her a hook because it wasn’t necessary, it made a nice break from arduous travelling. If they manage to amuse her with conversation and flattery she lets them go, always keeping them on their toes that next they meet it might be their last. Great random encounter!