Xuc and the Alux

Illustration by Harry Trumbore

The moon hung over the ancient ruins of the great city of Mayapán late on night in 1977. Xuc (pronounced like Chuck) was just tending to the last his duties that night as the caretaker of the historical site when he became aware of odd noises coming from somewhere near to the ruins of the Temple of the Birds. Curious, and sensing that something was perhaps amiss seeing as the site was meant to be closed to visitors past 5pm, Xuc approached the temple and was confronted with an attack by a creature that he had previously assumed to be mythical.

The 'Mayan Pixie'
Xuc compared the sound to a machete chopping wood, and presumably wondered what on earth a woodsman would be doing in that area at the time. He unlocked the entry gate to the site and proceeded in the direction from which the odd sounds were emanating. He had just rounded the corner of the Temple of the Birds when a small clay pellet was flung from some unseen location - whizzing past dangerously close to his head.
Xuc compared the sound to a machete chopping wood, and presumably wondered what on earth a woodsman would be doing in that area at the time. He unlocked the entry gate to the site and proceeded in the direction from which the odd sounds were emanating. He had just rounded the corner of the Temple of the Birds when a small clay pellet was flung from some unseen location - whizzing past dangerously close to his head.
Ducking behind a mound of fallen masonry in alarm, Xuc could now hear a further barrage of the aforementioned pellets pelting the stonework defending him from the onslaught. The rain of rocks briefly paused, allowing Xuc to take a peek out from his hiding place to try and snatch a glance at where exactly the projectiles were coming from. He was utterly flabbergasted to see a tiny humanoid silhouetted in the pale moonlight. It had a disproportionately-large head, a jet-black beard and appeared to be wearing a white huipil (a traditional Mayan garment resembling a tunic). A full-sized machete was slung over the creature's shoulder, being almost as long as the bizarre critter was tall.
What happened immediately after this is unknown, but I think it is a fair assumption to say that Xuc likely ran from the scene in terror. However, his fear didn't stop him from returning the next morning to collect the pellets that had been thrown by the entity. He amassed about eight of the anomalous objects, and they were described as being roughly the size of walnuts and as having been apparently baked to the point that they were akin to bullets in terms of hardness.

Source
Apparently the original source for this story is an article written in Fate Magazine by one Bill Mack for the August 1984 issue of said magazine. He had personally spoken with Xuc in the late 1970s, and had been given the impression that he was a 'personable' and intelligent individual. When Mack expressed some skepticism as to the veracity of Xuc's claims, the caretaker then revealed the eight pellets he had recovered. Fate Magazine is obviously not available online - and so I instead found this story in 'Lost Cities of North & South America' by David Hatcher Childress.