Cannibalism at it's finest
The main weapon the Karankawa used was a longbows. They used very powerful and long bows and arrows. Long arrows are better for hunting fish under the water, that is mostly the reason they used such long arrow. They made and used many tools including knives, scrapers, and spear points.
The Karankawa practiced ritual cannibalism of blood enemies. They say this tradition is to prevent the victim from having a second or third life. The Karankawa believed that eating the victim transferred the courage and fighting skill from the victim to the person eating the victim.
What happened or what became of them
In 1685, explorer La Salle led a French expedition in search of the Mississippi River, but they landed in the middle of Karankawan territory.The explorer established an outpost near Matagorda Bay, and the Karankawas were not happy about this. So they captured a french man and sliced the the skin then ate meat off his body. So they slowly got killed off by white people and their diseases.
The karankawa were very tall and athletic.