Anger is a  generalized term, so does not work well for a distinct theme, but a more specific word would be blinded anger. Lucky is so frustrated in being treated like an object and being sold, even though he tries his hardest to keep his job intact. So the anger he displays is not in any terms of strict aggression towards one person. When Estragon goes to wipe his tears, he lashes out. He does this to get some sort of feeling back, that he has the ability to fight back, even though he does not.

 

                                In the novel Oryx and Crake after Jimmy's mom leaves and takes his favourite pet killer, he also moves in to a sort of angry mood. He does not converse with people as much, and is seen to lash out at his father. Jimmy generalizes his anger to those around him, the difference in the 2 novels is that Jimmy's live is given more potential as he is open to more opportunities, but Lucky being an old slave is nearing the end of his life and has no choices left.

 

                                Generalized anger is dangerous because it gives no reason as to why the person is specifically targeting another. In novels and plays this theme works to cause confusion and chaos around characters in the story line, and makes it difficult to pinpoint and change.