What follows is a collection of sources that in some way describe the Karankawa Indians’ cannibalism:
[1777-1783] Morfi’s Memorias para la Historia de Tejas and Historia de Texas: 1673-1779 and Morfi’s Historia
Author: Juan Agustín Morfi
Written in: 1777-1783
Description: Father Morfi wrote two histories of Texas: Memorias para la Historia de Texas and the Historia de Texas. Memorias, his first history, was a collection of documents that he planned to condense into a more concise history—Historia de Texas. He died before fully completing Historia but historian Carlos Castañeda published a rough draft in 1935. Of the two histories, Memorias has far more information on Texas’s Native Peoples.
Morfi wrote his history during the Karankawa-Spanish war. With that the case, Morfi found little issue depicting the Karankawas as demonic. But Father Morfi had never set foot in Karankawa territory. His only encounter with these coastal peoples likely occurred in San Antonio, with Copano mission Indians when he toured the northern borderlands with the new Commandant General of the Interior, Teodoro de Croix. Therefore, Morfi relied heavily on Father Gaspar de Solís’s 1767 journal for information on the Karankawas’ cultural practices (copying it word for word in instances). Nevertheless, Morfi does provide some unique information such as estimated population sizes.
Father Morfi’s histories have since become quite popular and set in stone the image of Karankawas as inherently hostile group. It mythologized the Karankawas as impossible to civilize—as a Peoples who “eat children.”
Juan Agustín Morfi, Excerpts from the Memorias for the history of the province of Texas: being a translation of those parts of the Memorias which particularly concern the various Indians of the province of Texas; their tribal divisions, characteristics, customs, traditions, superstitions, and all else of interest concerning them, trans. Carlos E. Castañeda and Frederick C Chabot (San Antonio: Naylor Publishing, 1932).
Further Reading: Juan Agustín Morfi, History of Texas, 1673-1779, trans. Carlos Eduardo Castañeda (Albuquerque: The Quivira Society, 1935), 15-43; Irving A. Leonard, review of History of Texas, 1673-1779 in The Hispanic American Historical Review 16, no. 2 (May, 1936): 229-232.
 “Journal of Stephen F. Austin on his first trip to Texas.”
Author: Stephen F. Austin
Written In: 1821
Description: This journal documents Stephen F. Austin’s first travels through Texas. His view on the Karankawas is extremely biased—they are Indians on the land he intends to colonize. Most of his information on the coastal Indians was steeped in Spanish propaganda. Infamously, Austin discusses that “there will be no way of subduing [the Karankawas] but extermination.”
Relevance: See pages 300-305.
Further Reading: Gregg Cantrell, Stephen F. Austin: Empresario of Texas (Austin: Texas State Historical Society, 2016).
[1831-1833] Texas: Observations, Historical, Geographical, and Descriptive, in a Series of Letters, Written during a Visit to Austin’s Colony, with a view to a permanent settlement in that country, in the Autumn of 1831 and Texas
Author: Mary Holley Austin
Written In: 1831-1835
Description: Holley-Austin wrote two books on Texas. Her first is in the form of a series of letters entitled, Texas: Observations, Historical, Geographical, and Descriptive, in a Series of Letters, Written during a Visit to Austin’s Colony, with a view to a permanent settlement in that country, in the Autumn of 1831. Her second book, Texas, condenses the information from her first historical work into a concise and informative guide for prospective emigrants. That was Holley-Austin’s main intention in writing these works–attract settlers to Texas. Her descriptions paint the country as a fairyland, despite the struggle many colonists had upon their initial settlement.
Holley-Austin received her information for these works from first-hand observations but mostly through speaking with those she encountered while living in Texas. Her most significant informer was Stephen F. Austin.
Mary Austin Holley, Texas: Observations historical geographical and descriptive in a series of letters written during a visit to Austin’s colony (Baltimore: Armstrong & Plaskitt, 1833), 8, 95-97, 102-104.