Goblet of Fire
As Molly Weasley comes to watch Harry Potter during The Triwizard Tournament, she mentioned Ogg, who was the gamekeeper while she was at Hogwarts. While she was there she was also intrigued at the Whomping Willow, which wasn't planted until 1971. 
 Personality and skills
Due to Ogg's name, it is presumed that he may be non-human.