In his autobiography, Number 1, Billy Martin told about hunting in Texas with Mickey Mantle. Mickey had a friend who would let them hunt on his ranch. When they reached the ranch, Mickey told Billy to wait in the car while he checked in with his friend. Mantle's friend quickly gave them permission to hunt, but he asked Mickey a favor. He had a pet mule in the barn who was going blind, and he didn't have the heart to put him out of his misery. He asked Mickey to shoot the mule for him.

When Mickey came back to the car, he pretended to be angry. He scowled and slammed the door. Billy asked him what was wrong, and Mickey said his friend wouldn't let them hunt. "I'm so mad at that guy," Mantle said, "I'm going out to his barn and shoot one of his mules!" Mantle drove like a maniac to the barn. Martin protested, "We can't do that!" But Mickey was adamant. "Just watch me," he shouted.

When they got to the barn, Mantle jumped out of the car with his rifle, ran inside, and shot the mule. As he was leaving, though, he heard two shots, and he ran back to the car. He saw that Martin had taken out his rifle, too. "What are you doing, Martin?" he yelled. Martin yelled back, face red with anger, "We'll show that son of a gun! I just killed two of his cows!" Anger can be dangerously contagious. As Proverbs puts it, "Do not make friends with a hot-tempered man ... or you may learn his ways" (Proverbs 22:24-25).