Lennie

1. Loves animals

1.1. wants to take care of dog puppy

1.2. wants to save a rat

2. Causes problems

2.1. Beats farm owner's son

3. Physically strong

3.1. Can't control his strength

3.1.1. Finally accidentially kills a dog and a woman

4. Not very clever

4.1. His friend George got to solve many problems on behalf of Lennie

5. Kind

5.1. Doesn't want to hurt anybody...