He was notoriously abusive towards the juvenile performers he supposedly adored onscreen. For one scene in
Il mercante di schiavi (1937), he had to slap his 16 year-old co-star
Mickey Rooney across the face. Beery didn't fake the action and, without warning, slapped Rooney so hard he was knocked to the floor, spoiling the take and causing outrage among the crew. Director
Tay Garnett took Beery aside and told him that everyone on the set loved Rooney, and that it would be most unfortunate if some lighting equipment were to "accidentally" fall on Beery's head. Beery got the message and behaved himself for the rest of the shoot. Interestingly, Rooney was one of the very few actors to work with Beery who later expressed no resentment towards him. He said, "Not everyone loved him the way I did".
When
Dickie Moore interviewed former child stars for his 1984 book "Twinkle, Twinkle, Little Star" Wallace Beery and W.C. Fields were the two actors the child stars disliked working with the most.
Jackie Cooper said about Beery "We did four long films together" and "They couldn't find eight guys to carry his casket.".
