The Tinman wanted a heart, the Scarecrow wanted a brain and the Cowardly Lion wanted courage.
What did the scarecrow lack in the Wizard of Oz?
The “mindless” Scarecrow joins Dorothy in the hope that The Wizard will give him a brain. They are later joined by the Tin Woodman and the Cowardly Lion. When the group goes to the West, he kills the Witch’s crows by twisting their necks.