What follows is a collection of sources that in some way describe the Karankawa-individual Antonio:
[1829-~1850] Reminiscences of Mrs. Annie Fagan Teal
Author: Annie Fagan Teal (need to write one)
Written in: 1897
Description: At the age of 83, Mrs. T.C. Allan interviewed Annie Fagan Teal, an early settler of Texas. A transcript of this interview has yet to be uncovered (it’s unlikely one exists). Allan edited her conversation with Teal into this piece originally published in a local Victoria magazine called By The Way. This source, then, is far removed from the time in which the events described occurred. And moreover, we are receiving information second-hand. Nevertheless, Teal accurately describes that the first settlers of Texas had multiple positive interactions with Karankawas. This is important because later historians and colonists depicted Karankawas as inherently hostile at the first sign of Whites.
(1) Annie Teal enters Texas in 1829 at the age of 15. Around this time she is welcomed in a near-by Karankawa camp and drank “beer” with these Peoples. By beer, she could plainly mean any sort of alcoholic beverage or perhaps a caffeinated drink that the Karankawas made out of the yaupon leaves. [317, 320]
(2) Cholera broke out among those living in Texas. Without a doubt, it affected Native Peoples. 
(3) Teal is married in 1833 at the age of 19. Invited to her wedding is the Karankawa chief Prudencia. 
(4) Teal describes Karankawas finding work among the early settlers. It also discusses Karankawas drinking whiskey. 
(5) Discusses a custom of Indians of the area sending a young child to the houses of colonists asking for lodging to test the true “friendship” of the colonizers. I have not found any corroboration of this elsewhere. 
(6) Teal says that “Mexican hirelings” killed a Karankawa child and that the Karankawas took revenge by killing six. When militia followed the Karankawas, they turned back when the Karankawa chief Antonique (Antonio) readied to fight them. 
(7) Teal tells that Tonkawas killed eleven Karankawas when the Karankawas planned to attack the De León colony. I have also not found any validation for this story, but that the Karankawas had a conflict with De León is well-known. So too that De León had crafted a strong relationship with the Tonkawa Peoples. [322-323]
Further Reading: Ana Carolina Castillo Crimm, De León: A Tejano Family History (Austin: University of Texas Press, 2003).