Planetina has existed since the 1990's, as stated by Planetina herself. She was also seen being summoned by the Tina-Teers in an old television series from the same decade.

In present day, Planetina catches Morty's attention when she stops an evil rat alien named Diesel Weasel. Morty promptly asks her on a date, to which she accepts. After a fire, Morty confesses how he likes her and she is flattered before introducing him to her "children", who treat her like an item. She soon has an interview with the media until becoming surprised when Morty states they are a couple.

Planetina and Morty officially become a couple after a series of dates. However, the Tina-Teers are annoyed by the relationship and want to get rid of Morty for Planetina to focus on making them profits. This causes Morty to go on a murder spree of the Tina-Teers and their potential customers until he obtains their rings. Now free, she and Morty want to be together but his mother forbids it, causing Morty to leave home.

While trying to save the Earth with Morty, without the Tina-Teers to reign her in, Planetina's behavior starts to become increasingly violent starting with slashing the tires on a highway full of cars and then, burning down a congressman's home with a petrol bomb which begins to horrify Morty. Afterwards, at a mining facility, the two confront a group of miners who are about to go underground while Planetina is telling them what their actions are doing to the planet, but they refuse to listen and proceed underground to resume their mining. Although Morty says they'll get them next time, Planetina flies into a fit of rage and burns the entire mining facility to the ground resulting in the deaths of 300 people while Morty watches in tears. These actions cause Morty to decide to tearfully end their relationship amid Planetina's attempts to justify her actions at the mine from his bedroom window. She also brings up how he killed the Tina-teers, while he states he killed them because they were just going to sell her away and only wanted her free. Planetina then confesses her love for him but he sadly rejects her declaration. Distraught at the rejection, she tearfully curses Morty out before flying away into the night heartbroken, leaving Beth to comfort her heartbroken son.

Planetina is a humanoid Elemental construct resembling a teenage girl. She has very pale blue skin, turquoise hair and dark blue lips. She is always seen wearing her superhero-esque suit, which is primarily light blue with accents of yellow and includes the recycling symbol, in the shape of a heart, situated on her chest.

When Planetina becomes enraged, she becomes ignited in red flames and her skin and hair shift into a greenish tint. She also gains dark circles around her eyes and her hair begins floating upwards.

When Planetina was first introduced in her debut episode, she was shown to be incredibly approachable and kind. She instantly formed a bond with Morty and even became infatuated with him very quickly. Planetina also enjoyed her role as a superhero and was joyous whenever she completed a job. She often made quips whilst doing so and appeared to break the fourth wall by addressing the audience, telling them they are the solution to Earth's pollution. Although Planetina was quite happy with her life, she was put under pressure by the Tina-Teers to avoid eating too many calories and disliked being unsummoned by their elemental rings as it took away her autonomy.

However, as Morty got to know Planetina more, a fanatical side to her activism was revealed. She began engaging in acts of eco-terrorism, such as vandalising cars and bombing the homes of congressmen, and did so with just as much glee as she would with an act of heroism. This came to a head when she attempted to convince miners to stop working and after they refused, she murdered all of them in a fit of rage. Despite Morty being repulsed by this, Planetina remained headstrong in her beliefs and asserted that the miners deserved to die because of the impact they were having on the Earth's climate crisis