Achilles is Phoebus' horse who appears in The Hunchback of Notre Dame and its sequel. He is much snarkier in the sequel and answers rhetorical counting questions that Phoebus poses by tapping his hoof repeatedly.
His name was purely based around one joke - the "Achilles, heel!" line in the original movie. He quite nearly ended up nameless, but due to that one play on words, he received his name.
Also later in the first film, during the final fight, Phoebus says, "Achilles, sit," and the horse sits on the head of an enemy soldier. He gave him the same command to sit on a Brutish Guard upon being introduced. In the second film, during the Festival of Love, he found love in the end.
Achilles and his owner Phoebus are first seen exploring the town of Paris after the musical number Out There where he tells two guards that he is looking for the palace of justice but they ignore him. Later when the Brutish and Oafish guards attack Esmeralda and Esmeralda escapes, the two guards try to chase her but then bump into Achilles where Phoebus tells him to sit down. When Phoebus asks the guards to be escorted, the two escort him to the Palace of Justice. Achilles and Phoebus are briefly seen during the musical number Topsy Turvy following Frollo's guards to their master and later during the part where Frollo tasks Phoebus to find Esmeralda.
Achilles later appears briefly during the scene when Frollo's guards prepare an ambush in Paris to look for Esmeralda and later during the final battle when all the citizens are fighting against Frollo's guards including the part where Djali hits into the and Phoebus tells him to sit.
Achilles returns in this sequel and has a minor role. He first appears during the song "Le Jour D'Amour" where Esmeralda kisses Phoebus as Achilles smiles. He is later seen when Phoebus witnesses many people who lost their money stolen by Sarousch and after Phoebus explains to Zephyr that the circus owner who attracts people is actually a thief.
Achilles later appears when Phoebus holds a poster to know if the citizens saw Madellaine in which none of them know if they saw her. He is last seen when Phoebus and the other guards are planning to capture Sarousch. Later on at the Festival of Love, an unknown named female horse walks up to Achilles and they confess their love for each other and walk away together.
- Achilles was named after the Greek hero from Greek Mythology.
- A running gag is Phoebus telling Achilles to sit which results in Achilles comically sitting on a person.
- In the original novel and other adaptations, Phoebus's horse has no name and is given a name in the Disney version.
- Achilles's name was completely improvised by Kevin Kline (the voice of Phoebus).