The Haughty Maid of Logre’s horse, at least according to her own statement.
This well trained little mount waited in a garden of a city (Orquenseles?) just over the Galloway border, while the Haughty Maid sent knights to fetch it out to her, and a tall knight sat in the garden warning them of dire consequences to themselves if they did.
Apparently the Haughty Knight of the Narrow Way waited somewhere outside to vanquish each knight who took the bait, though in Gawaine’s case other adventures happened to intervene.
The docile palfrey itself was presumably innocent of guile in all this, though at the same time it knew the routine quite well. Its head was black on one side and white on the other, somewhat reminiscent of Enide’s sorrel palfrey.