Neville is the first portrait ghost appearing in in Luigi's Mansion. Neville is the father of Chauncey and the twins and the husband of Lydia. Luigi encounters Neville in the Study, in Area One, where Luigi can attempt to suck him up in the Poltergust 3000. His weakness is when he yawns because his heart is exposed, making him vulnerable to Luigi's attacks.
Luigi can read books in Neville's study. For example, he can read Neville's Big Baby Care Diary, which gives Luigi hints on how to beat Henry and Orville in hide-and-seek. He can also read Lydia's diary, which says how to summon Henry and Orville, which is by twirling their helicopter.