Clove Hitch, memorized. I’ve got a knot book out of the library now; if it’s good I’ll post it.
Hasufel has written 2 entries about this goal
I know how to tie a quick-release knot. Pull on the end, and it all comes undone (and your horse is freed).
The picture is of a Clove Hitch, which looks easy if I can just memorize it.

