@TobyLobster - thank you so much for this final and fastest version of the dragon!
As a result I've been able to incorporate your code into my final version of my landscaping project, being able to keep the Mode 1 graphics and including a game to find the dragon. There was even memory left over to include instructions for the game. I had to reduce detailing on the tower and reduce variable/procedure names to an absolute minimum to gain the memory I needed.
The code simply assigns a random hidden position on the grid for the dragon and calculates the distance from the player each time, essentially playing a game of "warmer or colder" as you get closer.
A reminder of the keys for the game: 1-4 allows you to look either N,E,S or W and the "M" key will move you one space in the direction you are looking.
When you land on the square where the dragon is, you are rewarded with the dragon graphic.
From my perspective, this provides a great conclusion to the project.
But I'm happy to see how far everyone else can take this to provide an even closer approximation to the original Lords of Midnight game.
Here's the code:-
https://bbcmic.ro/#%7B%22v%22%3A1%2C%22 ... PROC%22%7D