David Freidel et al. discuss the use of litters in Mesoamerica and the use of battle beasts.
David Freidel, Linda Schele, and Joy Parker, Maya Cosmos: Three Thousand Years on the Shaman’s Path (New York: William Morrow and Company, 1993), 310–14
BATTLE BANNERS AND LITTERS
Hawaw-Ka'an K'awil of Tikal, also known as Ruler A and Ah-Kakaw, used Tlaloc warfare to avenge the terrible defeats visited upon his kingdom by his enemies over a span of more than a hundred years. To celebrate his victory over the enemy who had captured and sacrificed his own father, he commissioned two lintels. Each lintel showed him with a different battle beast: the Jaguar Protector who gave him victory over his father's killers and the great War Serpent who symbolized the great victory on the ancestral past—Jaguar's Paw's triumph over Waxaktun. These images were carved on the underside of the lintels inside his funerary temple. The lintels convey not only the power of the supernaturals conjured by the vision rites but the fact that there were many battle beasts presiding over way and royal sacrifice.
Lintel 2 of Temple (Fig. 7:18a) shows Hawaw-Ka'an-K'awil wearing the balloon headdress of Tolaloc-Venus warfare adopted at the time of the Waxaktun conquest, and holding the bunched javelins and shield, the original metaphors for war imported from Teotihuacan. He sits in a majesty on the litter that carried him into battle, while above him hulks Waxaklahun-Ubah-Kan, the great War Serpent, Standing in front of the litter is a standard marked with a trapezoidal Year Signs of the Tlaloc complex and sporting the Waxaklahun-Ubah-Kan at its summit. This image is meant to evoke the Tlaloc standard taken to battle against Waxaktun by his glorious ancestor. The scene also depicts the king in the same battle costume worn by Curl-Snout on the sides of Stela 31, a monument Hasaw-Ka'an-K'awil honorably buried inside Temple 33.
In the complementary lintel over the innermost door (Fig. 7:18b), the king depicted himself in a different litter, this one bearing the huge Jaguar Protector named Nu-Balam-Chaknal. Here the battle standard is decorated with three bundled and tasseled shields, and at its summit perches the bleeding jaguar head we saw on the bone throne in the Tablet of the Sun at Palenque. The massive image of the jaguar looms protectively over the king reaching out with its great claws to threaten those who come against him.
The text of Lintel 3 confirms its association with warfare. The first event recorded tells us that the flint-shield of an enemy king, Jaguar-Paw of Kalak'mul, was put down. Forty days later, while sitting in the Nu-Balam-Chaknal litter, Hawaw-Ka'an-K'awil conjured a god, probably Nu-Balam-Chaknal himself, by piercing his tongue in self-sacrifice. He did this on the day that he dedicated the final phase of Temple 33, which contained Stela 31, the big-stone memorializing the Waxaktun conquest. This stela, and other sacred big-stones set before the human-made mountains of the North Acropolis, had been broken and desecrated by the Dos Pilas conquerors who had killed his father. Deep in that same building lay the tomb of Stormy-Sky, the grandson of the conqueror and the king who had commissioned Stela 31. Moreover, the Kalak'mul king he captured and killed in the dedication rites for this building was the head of the alliance that killed his father and an even earlier ancestor more than a century earlier. It was a sweet vengeance that still speaks loudly across the ensuing centuries.
Graffiti drawings scratched on the walls of Tikal palaces, depicting the conjuring of supernatural beings from the Otherworld, prove that these scenes were more than imaginary events seen only by the kings. Several of these elaborate doodles (Fig. 7:19) show the great litters of the king with his protector beings hovering over him while he is participating in ritual. These images are not the propaganda of rulers, created in an effort to persuade the people of the reality of the supernatural events they were witnessing. They are the poorly drawn images of witnesses, perhaps the minor members of lordly families, who scratched the wonders that they saw during moments of ritual into the walls of the places where they lived their lives.
Another graffito at Holmul (Fig. 7:20) depicts a lord on a great rattle-snake litter being carried by bearers. We can't be sure that Maya kings went to war seated on such litters, as the Mexica lords did, but they certainly rode the in the great processions that led into the grand plazas where they sacrificed their enemies. These great palanquins were real objects that focused the supernatural powers of the Otherworld for ritual and battle. We also know that these litters could be captured when their owners were defeated.
K'in-Balam, the Sun-Jaguar, of Tikal appears to have been lost in battle against the very enemies who killed Hawaw-ka'an-K'awil's father, Shield-Skull. That unfortunate Tikal king lost a war to Flint-Sky-God K, the extraordinary lord of Dos Pilas who acknowledged in his inscriptions that he was a vassal lord of the king of Kalak'mul. A remarkable hieroglyphic stairway at Dos Pilas recounts how Shield-Skull's flint-shield was "brought down" by Flint-Sky-God K on May 3, A.D. 679.