1. Prideful: When Bob Ewell walks up to the stand to testify, Lee describes him as "a little bantam cock of a man," which is comparing him to a strutting rooster, who is there to prove his territory, to stake his claim, and to proudly declare the courtroom his-just like a rooster who struts around the henyard declaring his is the master of that realm. He confidently answers most questions, even being disrespectful, calling his lawyer "cap'n". He is so confident and prideful that he will win the case, that he knows he can do or say what he wants.
2. Lazy: in the second paragraph of chapter 27, we find out that Bob
"acquired and lost a job in a matter of days...and he was the only man I have ever heard of who was fired from the WPA for laziness."
He couldn't even hold a job that was given to him out of pity.
3. Vengeful: since his pride was wounded in court, because Atticus made it quite clear what a scoundrel he was (even though he won the case), Bob's pride was wounded. In the beginning of chapter 23, Bob walked up to Atticus and "cursed him, spat on him, and threatened to kill him." So, he is vengeful and threatening to Atticus, and later follows through on these threats when he attacks Jem and Scout.
4. Drunk and Abusive: through Mayella's testimony in chapter 18, even though she tries to hide it, it becomes quite apparent that her dad is a lousy drunk, and abusive to the children. She almost slips up and says that Bob is "tollable, 'cept when-" and was probably going to say, "when he's drinking, because then he gets mean and beats us," but she stopped herself in time.
I hope that those words and quotes can get you started. Good luck!