-i

-i is the X-Antibody of i and the manifestation of the imaginary number's inverse. -i is very optimistic and tries to spread her positivity wherever she goes. She also tries to keep Fred's spirits up, especially when i taunts him. Unfortunately, the conflict between -i and i usually impacts Fred for the worse.

Like i, -i does not exist either. This bamboozles Fred to no extent.

Background
-i was created by Fred to counter i's mischief. Fred secretly threw a bit of salt (contaminated with the X-Virus) over his left shoulder, where i usually perched. The next time i popped out to mock Fred again, he got infected.

After a week or so, the symptoms were clear. i was unable to talk and could barely flap his bat-like wings. His indigo color had also become a pale lavender. Finally, a month after getting infected, i coughed out the black X-Antibody fluid. However, something unusual happened. The fluid, instead of forming into the X-Antibody, glowed purple, then vanished!

Fred, trying to figure out what happened, was alerted by a second creature perching on his right shoulder. He looked over to see what had happened.

The fluid had evidently summoned -i from the abstract world. -i smiled at Fred, then began helping him out by organizing all his files and folders. Somehow she knew exactly what Fred wanted done.

Then she became Fred's companion, following him everywhere and giving him advice and opinions on daily, routine decisions. Whenever i popped out to try and annoy Fred, -i did her best to keep Fred from losing self-esteem. So far, it's working pretty well.

Description
-i takes the form of a two-inch tall letter "i", in blocky sans serif font, colored light yellow. The tittle of the i is -i's head. Above that is a glowing yellow halo. -i has a set of green butterfly wings, with which she flies. The telltale "X" that shows -i is an X-Antibody is positioned at the top of -i's body, and is colored a deep violet. A minus sign trails -i to her immediate right (which is your left), hovering above the ground.

Personality
-i is very cheerful and outgoing. She enjoys conversation, and can often be seen at the Coffee Shop conversing with penguins from all walks of life. -i is also very helpful. Having a lot of spare time on her hands (as a number, she never needs to sleep and will "live" for all time), -i devotes a lot of it to community service and helping people in general. She is often part of Club Penguin Island's Party Set-Up Team, decorating the island with banners, floats, and the like to create a suitable festive atmosphere. Her main focus, however, is Fred, who is constantly agonized and mocked by her inverse, i. -i is pretty much the Antics Brothers' unofficial housekeeper, always tidying their igloo at the end of a long, tiring day.

She also has a strange relationship with i that can be compared to sibling rivalry. The two argue a lot, with i's sadism and trickery contending against -i's advice and suggestions. i always tries to embarrass or frustrate Fred, while -i tries to keep his spirits up. It would seem that they hate each other, but in reality, the two are like a brother and a sister. i and -i are always on speaking terms -- in fact, whenever they're not driving Fred nuts, they spend a lot of time chatting with each other. They also help each other out a lot. -i assists i take care of his precious garden, and i helps her decorate the island when she's on one of her party set-up errands. i and -i even share the same living space (a drawing of the complex plane located in Fred's spare notebook). As a result of all of this, the two are inseparable. i is extremely defensive of -i, whom he regards as his "little sister", and whenever the duo are in foreign areas, -i is very dependent on her "big brother".

Trivia

 * -i, like i, has no visible eyes. However, she does see using patches of skin sensitive to light that are located around the same place where her eyes should be. Her vision is not quite as sharp as penguins, but superior compared to jellyfish.
 * Even though -i doesn't exist, an X-Antibody was sent to "retrieve her" anyways during the Nightmare Epic. Said X-Antibody was thrown out the building Fred was in.