From the Super Mario Wiki
Tib is a character in Super Paper Mario who was held captive by Mimi in Merlee's Mansion. He is a poor boy with problems in his love life, having missed many chances to meet girls in the past because he's a bit clueless. After finally getting a girlfriend before the events of the game, he comes to the Mansion seeking Merlee so that she could read his fortune and tell him if the future for him and his girlfriend looked bright. Unfortunately, because of his clueless nature, he is kidnapped and forced to work for Mimi instead. After Mimi leaves, he and most of the prisoners are set free.