Someone who studies and collects information on flags.
2 Astacologist: A person who investigates and analyses crayfish.
3 Omnibologist: A bus-spotter, or someone who studies motor buses.
This hit the headlines recently thanks to Jeremy Paxman growing a beard. It means someone who makes studies of beards.
5 Sindonologist: One who studies the Shroud of Turin.
6 Philematologist: Someone concerned with the art and study of kissing.
7 Labologist: A person who studies and collects beer and wine bottle labels.
8 Ktenologist: One who studies the science of putting people to death.
9 Deltiologist: A person who collects and studies postcards.
10 Batologist: Someone who is concerned in the study of brambles.