Lucki meets him in Chapter Eleven after her pokemon are stolen by Team Magma, when the injured Tropius makes a failed attempt to attack two Team Magma grunts who have captured the rest of his herd. She quickly gives him the Sitrus berries she collected, allowing him to recover quickly enough that he manages to fly the two of them away just before Team Magma would have attacked, although his leaf wings have been badly damaged and shortly become useless and wilt off. He grows new ones by Chapter Thirteen but during the intervening time is earthbound.
The two team up to harass Team Magma during Chapter Twelve and delay them from leaving until Team Aqua arrives to defeat Team Magma and recover the stolen and poached pokemon. Afterward, he agrees to go with Lucki as her pokemon, making him her fourth pokemon. Based on his strength, especially in regards to durability, and his ability to use high-level moves such as body slam, his level is likely near or at forty. His name is a pun based on his serious nature.
In Chapter Fifteen, it is discovered that Team Magma later returned for a second attempt at poaching the areas' pokemon, this time successful.
Although a wild pokemon, Saurius is apparently capable of using some inherited moves, possibly through exposure.
Saurius' current moves:
- Fly (considered a naturally learned move in the fanon of the story)
- Razor leaf
- Body slam
- Magical leaf
- Leech seed