Transformation is episode 20 of Teen Titans series and the seventh episode of season 2.
Starfire's happy life suddenly takes an abrupt turn for the worse when a large lump pops up on her forehead ... and that is just the beginning. As the days pass, her body begins to develop new mutations, making her feel horrible because she fears that she is turning into a monster. She more and more shies away from her friends and hides her new deformities under heavy clothing.
Then the Titans receive an emergency call about Plasmus, who is ripping up a stadium in search of a nourishing sewer pipe. When the Titans engage him, they come to notice Starfire's problem for the first time. After Plasmus blasts off her protective clothes, exposing her mutations, Starfire flies off into space in shame. Thinking that she now has no home to return to, she attempts to find aliens whose mutations match her own, but in each attempt she is met with fear and revulsion. The other Titans, worried about her, modify the T-Ship for space travel and set off after her, tracing her route through the alien planets she has visited.
Eventually, Starfire arrives on a strange planet where, following a violent encounter with a flesh-eating plant, she encounters a beautiful humanoid woman who sheds some light on her current condition: Starfire is undergoing the Transformation, the biological passing of Tamaraneans from prepubescence to puberty. Starfire's transformations were so bizarre because she is turning into a special type of pubescent called Chrysalis. But before Starfire can ask more, a cocoon forms around her, entrapping her. And then the woman reveals her true self: she is actually a member of a hostile alien species who are specialized in hunting Chrysalises, whom they consider a special, if rare, delicacy.
But before the Chrysalis Eater can begin its feast of Starfire's flesh, the other Titans arrive and interfere. Robin frees Starfire from her cocoon and shows her that she has reverted to her former appearance, though with one improvement: she can now fire starbolts out of her eyes. With this new ability, she blasts the Chrysalis Eater onto the surface, where it is devoured by the flesh-eating plant Starfire had met earlier. With the reassurance that the other Titans will always be her friends, no matter how much she changes on the outside, Starfire returns home, happy once again. But then it is said that Beast Boy gained the chicken pocks...
- This episode's story is a version of Hans Christian Andersen's fairy tale The Ugly Duckling.
- The scene in which the T-Ship escapes a beast that appeared to be a planet references Star Wars: The Empire Strikes Back.
- The episode is actually narrated in third-person limited in a few scenes. An unknown narrator tells the story from a book and zooms in on Starfire.
- List of Starfire's conditions of puberty;
- Big Pimple (turn to horn)
- Tusks on her neck.
- Big ugly fingernails.
- Weird craving for unusual food.
- Point Ears.
- Scaly skin.
- Big hairy feet.
- It is revealed that Blackfire once turn Purple for 2 days when she was in her puberty.
- This episodes unites Catherine Cavadini and Tara Strong who have previously voiced Blossom and Bubbles in The Powerpuff Girls.
- Narrator: Long ago on a small blue planet called Earth, there was a young alien girl who lived in a T.
- Starfire: My friends must not see how hideous I have become or they will surely think I am turning into some sort of horrible monster. I must never allow anyone to see me... ever again.
- Robin: I don't know what's more disgusting, Plasmus: The way you look, or the stuff you eat.
- Beast Boy: Orange-flavored bad guy? Gross! Yet... strangely refreshing.
- Robin: Cyborg, how long until we can launch?
- Cyborg: Oh, about five minutes after you QUIT ASKING ME THAT!
- Narrator: So the happy, young girl returned home with her friends, and they all lived happily ever after. That is… until Beast Boy got the chicken pox.