'El Moro' was a horse.
Here's a communique I received from an old friend in Colombia who deals in emeralds.
"Peter Rainier, the author of Green Fire, introduced tea to Colombia, initially an unpopular heresy in caffeineophile Colombia interesting only to the relatively small Brit population. I spent many nights at his plantation, Las Cascadas, enroute from Gachalá to Chivor mine. By my era at the mine (1956), Rainier had already passed on, during a hotel fire in Canada. (the legend at Chivor said that those who stole from the mine would die a violent death). His veddy British sidekick Chris Dixon was still alive and always had a good story to tell. The bad guy mistakenly called Moro as you quote, was still trying to sue Warner Bros. for defamation of character. I used to give him a ride in my Nissan 4 wheel drive now and again. If memory serves me right, Moro was Rainier's favorite Paso Horse. Interestingly, I first saw the movie in Honolulu on liberty from Sand Island CG Station, never remotely dreaming that I would soon be at the real mine from which the story and the picture were taken.