Hermes is first seen at Hercules' baby shower, where he brings Hera flowers and compliments Zeus on the festivities. He is also seen when Hades enters the festivities.
Later on, Hermes catches sight of the Titans returning to Mount Olympus and quickly alerts Zeus, Hera, and the other gods for battle. He is the last god (aside from Zeus) to be captured, being kidnapped by Pain and Panic; the latter steals his glasses while the former barks into his ear. After Hercules arrives and frees the gods, Hermes regains his glasses and beats the imps with his staff.
During the finale of the film, Hermes is present to celebrate Hercules' success. He summons the Muses to sing an "A Star Is Born" as the film closes out as he plays the piano.
In the animated series, taking place during Hercules' training years on Phil's Island, Hermes makes occasional appearances and sometimes joins Hercules on one of his misadventures. For example, in "Hercules and the Bacchanal", he volunteers alongside Hercules in watching over Phil's island as the satyr leaves for the weekend. In "Hercules and the Romans", he is given the name of Mercury by Icarus.
Hermes made a few cameo appearances in the animated series. In "Donald Wants to Fly", his shoes are stolen by Donald Duck as he tries to teach himself how to fly, which goes unsuccessful.
Hermes' glasses seem to not just be aesthetic, he needs them to see clearly in the scene where the Titans storm Olympus.
Hermes design in the film is based off his voice actor, Paul Shaffer's, appearance, who also wears round glasses and plays piano.
In Greek mythology, Hermes was also the god of shepherds, travelers, merchants, thieves, and all others who lived by their wits. Like most of the major gods, he was a son of Zeus. Even though Hermes was the god of liars and thieves, he never stole or lied - but he often didn't tell the whole truth.
Hermes' Roman counterpart is named Mercury, which is also the name of a chemical element found inside thermometers, as with the innermost and smallest planet in our Solar System.