For the first poster I chose this because it represents the thief that stole lightning. I simplified my subject by making the lighting bolt myself. The texture I used for the outline for the lightning bolt.

For the second poster I chose the tree house because it the main idea/point of the whole book series. I simplified it by not going in detail when making the tree. 

For the third poster I did the bat from Sand lot as it sent the ball over the wall. I simplified it by removing the nottom handle from the bat.