Aristo is a resident of Soleanna in Sonic the Hedgehog (2006). He is a clever young scientist from Soleanna Castle Town who is training to become a top mathematician. Due to his mathematical intellect, he was named after the Greek philosopher, Aristotle. He is evidently very intelligent, as he has challenged many people to intellectual battles, but no one has proven able to beat him.
In Sonic's story, Aristo gives Sonic his fifteenth Town Mission. Aristo decides to test the hedgehog's estimation skills in a series of five questions. For each question, Sonic must correctly guess the number of crates in a stack five times.