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The Fossil Maniac's house
The Fossil Maniac is a character in Ruby, Sapphire, and Emerald. His house is located on Route 114, just outside Fallarbor Town. The Fossil Maniac's brother, who also lives in his house, will hand out TM26 (Dig).
In Pokémon Emerald, after the National Pokédex is obtained, the player can go to the Desert Underpass through his house, where Ditto and the unchosen Fossil can be obtained (this is the only way to catch a Ditto except for trading in the Hoenn games). The sign outside his house states:
When checking on the display case inside, it states the following:
Rocks in peculiar shapes fill the display cases.