Grug is a fictional character from the animated film series called The Croods. He is depicted as a prehistoric caveman and serves as the father of the family. Grug is known for his protective nature and often prioritizes the safety of his family over everything else. In the story, Grug struggles with change and is initially resistant to new ideas. However, as the plot unfolds, he learns to embrace innovation and adapt to new challenges. His character represents the theme of growth and the importance of family bonds in the face of adversity.