Octavia is a background Earth pony who appears in the episodes "The Best Night Ever", "Sweet and Elite", "Inspiration Manifestation", and "Equestria Games"; she also appears in the IDW comics. She is unnamed in the series, but she is named in merchandise. She has a dark gray mane and tail, a light gray coat, light purple eyes, and wears a pink bow-tie with a white collar. She shares her eye design with Rarity, the spa ponies, and several background ponies, except for the iris. Her cutie mark is a violet treble clef, though the cello is most often notated with a bass clef. The cello is also normally played sitting down, although she plays standing, like a double bass. If it were a double bass, her cutie mark would still be conflicting because double bass is also usually written for in bass clef.
She plays a cello as part of a four-pony musical ensemble at the Grand Galloping Gala in the episode The Best Night Ever. She retains an apparently calm dignified expression when in costume, except when Pinkie Pie disturbs her. At Pinkie's request, the orchestra plays the Pony Pokey. Octavia Melody eventually falls over when Pinkie tries to make her play faster.
Octavia appears briefly in Sweet and Elite in the garden party scene, playing with a mostly-different musical ensemble.
She reappears in Inspiration Manifestation, switched from S04E16 Unnamed Earth Stallion #2 by a cursed Rarity during a filly's birthday party. In Equestria Games, Octavia is barely seen in the audience as Spike attempts to light the torch.