My heart became darker because of that," said Grendel when he first realized that he was immune to all weapons (p. 76). Throughout Grendel, by John Gardner, one can see that all of Grendel's actions are caused by several motives. Many things influenced Grendel's life but the most important were his habitat, his appearance, and his emotions.Grendel spent most of his time alone. He lived in a dark cave under water. Before he went up for the first time, he played with "imaginary friends" (p. 17). He had no one to talk to; and one can see that when he appeared for the first time at Hrothgar's meadhall. During this visit he said, "Why can't I have someone to talk to?" (P. 53). He realized that all the people; even the Shaper and Hrothgar had someone to talk to. These were some of the things that contributed the most towards Grendel's violent actions.Even though Grendel's habitat influenced his actions, his appearance also contributed towards it. Not only the other persons thought that Grendel was ugly, but even Grendel thought this. When Hrothgar saw Grendel for the first time, he thought that Grendel was "some beastlike fungus" (p. 24). And when Grendel was trapped between two branches, and he thought that he was going to die he said that he was "an ugly god pitifully dying in a tree!" (p. 22). His repulsing appearance also played a major role in Grendel's actions.All of these things affected both Grendel's mind and emotions. He changed his mind several times in a very short period of time. One can see this when he first wanted to kill the queen, and then he changed his mind. Grendel was also very confused because he didn't know why he existed or why he was there. Even when he was listening to the Shaper's song, Grendel "believed him," and he thought that he was a descendant of Cain. His lack of sense, and direction was also one of the factors which made Grendel act violent.Since his habitat, his appearance, and his emotions were either distorted or obscure, Grendel had a violent nature. His heart was "dark". And one can see this when Grendel was talking to the dragon. The dragon called him his "violent friend" (p. 74). Even Grendel said, "blood-lust and rage are my character" (p. 123).