Mini-Figurines are collectible key items in Final Fantasy IX. They serve no other purpose than raising the Treasure Hunter Rank.

Figurine Location
Mini-Cid Purchase from Treno Auction House.
Mini-Burmecia Inside the Tantalus play-house in Lindblum.
Mini-Brahne Examine the mayor's desk in Dali during Treno card tournament in disc 3. If missed, the player can return on disc 4 to get it by climbing the ladder in the top-left of the screen.
Mini-Prima Vista Complete the Morrid's Coffee sidequest.