This article contains information that relates to the non-canon game Pikmin: Ultimate Doom by Wraith.
The Gladiator's Stone is a special treasure found in Crystal Falls. It is the first treasure in the Elder Stone collection, and a key story point. Apollo constantly tries to unlock its power, going through extensive research and experimentation on it. Next to the Philosopher's Stone, it is one of the most important treasures in the game. It is apparently worth one hundred lifetimes of Pokos.
The Gladiator's Stone is an asymmetrical rock with designs etched onto its surface with red color. It pulmonates an aura of energy that visually looks like distortions one would find on a hot day. It is brown in color.