Mr. Sanders (full name Tom Sanders) is Lulu Sanders's father. Lulu's mother died when she was four. He studies animals for his profession, which often takes him around the world. Before Wiggins, he and Lulu lived in England for two years, where Lulu learned to ride ponies. When he took a job in the Amazon, Lulu moved to Wiggins to live with her father's mother, Grandmother Sanders. Later, he finds a job studying animals near Wiggins, so he comes back to live with Lulu and his mother. Lulu learns a lot about tracking animals and wilderness skills from him. When she was looking for a lost little girl, Rosalie Lacey, in the woods, she knew to look for identifying objects and tracks because of what her father had told her.