The name's English spelling is Philomena, though on the show's storyboard by Sabrina Alberghetti it shows up as "Philemena". One of Hasbro's online coloring pages, a question on Hasbro's My Little Pony Facebook page, and a tweet by Hasbro's My Little Pony Twitter account spell the name "Philomeena". The 2012 My Little Ponytrading cards use "Philomena" and list it as a trademark.
Philomena appears in A Bird in the Hoof, introduced at the party held at Sugarcube Corner in honor of Princess Celestia's visit. The bird initially appears to be very sickly, coughing and molting uncontrollably. Fluttershy, worried at the sickly state of the bird, takes Philomena away to her home without telling anyone so that she can heal her properly. Throughout the episode, Fluttershy tries desperately to heal Philomena, but she has never seen a bird quite like it and all her attempted treatments seem to make its condition worse. The bird eventually escapes, leading Fluttershy and Twilight Sparkle into a chase around Ponyville to catch her. They eventually find her, but when she loses her last feather, Philomena bursts into flames. As Fluttershy cries at the sight of the ashes, Princess Celestia arrives. The princess bends her head down over the pile of ash and tells her incinerated pet to stop fooling around and scaring everypony. Suddenly, Philomena rises again, renewed and in better shape.
"I'm afraid mischievous little Philomena here took the occasion to have a little fun with you, Fluttershy. Say you're sorry, young lady."
Princess Celestia explains to Fluttershy that Philomena, like all phoenixes, plucks all her feathers and burns into ashes at the end of her life cycle, only to rise from the ashes and renew herself. Princess Celestia describes her pet bird as being mischievous, prompting her to apologize for all the trouble she had caused. Philomena herself is even shown blushing and behaving rather regretfully towards Fluttershy. As the newly revived phoenix begins flying around for a bit, she intentionally drops one of her feathers into Fluttershy's mane, much the pony's delight. Soon after, Rainbow Dash gets Philomena to tickle the Royal guards on the nose as a prank; when they successfully make the guards laugh, they share a high five.