Show and Tell is a sidequest primarily available in Fossil Fighters: Champions. To complete it, the player must go to the second floor of the Ilium Village Fighter Station and talk to the little girl named Petula. She will ask you to Fossil Battle her using three specific Vivosaurs.
When you first battle her, you are mandated to use Nigo, Peloro, and Coelo. She uses three Rank 6 Vivosaurs- Krypto, Raja, and Berto.
The second time you battle her, she requires you to use Parapu, Desmo, and Gaudry. She uses a Rank 12 Dacerus, a Rank 12 Ryden, and a Rank 12 Hopter.